Auto merge of #120524 - Nadrieril:rollup-67952ib, r=Nadrieril

Rollup of 9 pull requests

Successful merges:

 - #120207 (check `RUST_BOOTSTRAP_CONFIG` in `profile_user_dist` test)
 - #120321 (pattern_analysis: cleanup the contexts)
 - #120355 (document `FromIterator for Vec` allocation behaviors)
 - #120430 (std: thread_local::register_dtor fix proposal for FreeBSD.)
 - #120469 (Provide more context on derived obligation error primary label)
 - #120472 (Make duplicate lang items fatal)
 - #120490 (Don't hash lints differently to non-lints.)
 - #120495 (Remove the `abi_amdgpu_kernel` feature)
 - #120501 (rustdoc: Correctly handle attribute merge if this is a glob reexport)

r? `@ghost`
`@rustbot` modify labels: rollup

245 files changed, 772 insertions, 903 deletions

diff --git a/compiler/rustc_codegen_cranelift/src/abi/mod.rs b/compiler/rustc_codegen_cranelift/src/abi/mod.rs
index abd70dd4458..0f0d828c8fc 100644
--- a/compiler/rustc_codegen_cranelift/src/abi/mod.rs
+++ b/compiler/rustc_codegen_cranelift/src/abi/mod.rs
@@ -56,11 +56,7 @@ pub(crate) fn conv_to_call_conv(sess: &Session, c: Conv, default_call_conv: Call
             sess.dcx().fatal("C-cmse-nonsecure-call call conv is not yet implemented");
         }
 
-        Conv::Msp430Intr
-        | Conv::PtxKernel
-        | Conv::AmdGpuKernel
-        | Conv::AvrInterrupt
-        | Conv::AvrNonBlockingInterrupt => {
+        Conv::Msp430Intr | Conv::PtxKernel | Conv::AvrInterrupt | Conv::AvrNonBlockingInterrupt => {
             unreachable!("tried to use {c:?} call conv which only exists on an unsupported target");
         }
     }
diff --git a/compiler/rustc_codegen_llvm/src/abi.rs b/compiler/rustc_codegen_llvm/src/abi.rs
index 0718bebb31b..b5b4f894e4d 100644
--- a/compiler/rustc_codegen_llvm/src/abi.rs
+++ b/compiler/rustc_codegen_llvm/src/abi.rs
@@ -590,7 +590,6 @@ impl From<Conv> for llvm::CallConv {
             Conv::Cold => llvm::ColdCallConv,
             Conv::PreserveMost => llvm::PreserveMost,
             Conv::PreserveAll => llvm::PreserveAll,
-            Conv::AmdGpuKernel => llvm::AmdGpuKernel,
             Conv::AvrInterrupt => llvm::AvrInterrupt,
             Conv::AvrNonBlockingInterrupt => llvm::AvrNonBlockingInterrupt,
             Conv::ArmAapcs => llvm::ArmAapcsCallConv,
diff --git a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs b/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
index ee73c6b4756..4ad44a42738 100644
--- a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
+++ b/compiler/rustc_codegen_llvm/src/llvm/ffi.rs
@@ -106,7 +106,6 @@ pub enum CallConv {
     X86_Intr = 83,
     AvrNonBlockingInterrupt = 84,
     AvrInterrupt = 85,
-    AmdGpuKernel = 91,
 }
 
 /// LLVMRustLinkage
diff --git a/compiler/rustc_errors/src/diagnostic.rs b/compiler/rustc_errors/src/diagnostic.rs
index bf1ab37a1cf..b87eef07fd5 100644
--- a/compiler/rustc_errors/src/diagnostic.rs
+++ b/compiler/rustc_errors/src/diagnostic.rs
@@ -109,8 +109,6 @@ pub struct Diagnostic {
     /// `span` if there is one. Otherwise, it is `DUMMY_SP`.
     pub sort_span: Span,
 
-    /// If diagnostic is from Lint, custom hash function ignores children.
-    /// Otherwise hash is based on the all the fields.
     pub is_lint: Option<IsLint>,
 
     /// With `-Ztrack_diagnostics` enabled,
@@ -980,22 +978,24 @@ impl Diagnostic {
     ) -> (
         &Level,
         &[(DiagnosticMessage, Style)],
-        Vec<(&Cow<'static, str>, &DiagnosticArgValue)>,
         &Option<ErrCode>,
-        &Option<IsLint>,
         &MultiSpan,
+        &[SubDiagnostic],
         &Result<Vec<CodeSuggestion>, SuggestionsDisabled>,
-        Option<&[SubDiagnostic]>,
+        Vec<(&DiagnosticArgName, &DiagnosticArgValue)>,
+        &Option<IsLint>,
     ) {
         (
             &self.level,
             &self.messages,
-            self.args().collect(),
             &self.code,
-            &self.is_lint,
             &self.span,
+            &self.children,
             &self.suggestions,
-            (if self.is_lint.is_some() { None } else { Some(&self.children) }),
+            self.args().collect(),
+            // omit self.sort_span
+            &self.is_lint,
+            // omit self.emitted_at
         )
     }
 }
diff --git a/compiler/rustc_feature/src/removed.rs b/compiler/rustc_feature/src/removed.rs
index 67ee53d8ae5..85fcf6a9994 100644
--- a/compiler/rustc_feature/src/removed.rs
+++ b/compiler/rustc_feature/src/removed.rs
@@ -32,6 +32,8 @@ declare_features! (
     // feature-group-start: removed features
     // -------------------------------------------------------------------------
 
+    /// Allows using the `amdgpu-kernel` ABI.
+    (removed, abi_amdgpu_kernel, "CURRENT_RUSTC_VERSION", Some(51575), None),
     (removed, advanced_slice_patterns, "1.0.0", Some(62254),
      Some("merged into `#![feature(slice_patterns)]`")),
     (removed, allocator, "1.0.0", None, None),
diff --git a/compiler/rustc_feature/src/unstable.rs b/compiler/rustc_feature/src/unstable.rs
index e66a66e23dc..643185ba20a 100644
--- a/compiler/rustc_feature/src/unstable.rs
+++ b/compiler/rustc_feature/src/unstable.rs
@@ -321,8 +321,6 @@ declare_features! (
     // feature-group-start: actual feature gates
     // -------------------------------------------------------------------------
 
-    /// Allows using the `amdgpu-kernel` ABI.
-    (unstable, abi_amdgpu_kernel, "1.29.0", Some(51575)),
     /// Allows `extern "avr-interrupt" fn()` and `extern "avr-non-blocking-interrupt" fn()`.
     (unstable, abi_avr_interrupt, "1.45.0", Some(69664)),
     /// Allows `extern "C-cmse-nonsecure-call" fn()`.
diff --git a/compiler/rustc_middle/src/ty/layout.rs b/compiler/rustc_middle/src/ty/layout.rs
index f07a4ac29e9..73b0e324f13 100644
--- a/compiler/rustc_middle/src/ty/layout.rs
+++ b/compiler/rustc_middle/src/ty/layout.rs
@@ -1247,7 +1247,6 @@ pub fn fn_can_unwind(tcx: TyCtxt<'_>, fn_def_id: Option<DefId>, abi: SpecAbi) ->
         PtxKernel
         | Msp430Interrupt
         | X86Interrupt
-        | AmdGpuKernel
         | EfiApi
         | AvrInterrupt
         | AvrNonBlockingInterrupt
diff --git a/compiler/rustc_mir_transform/src/ffi_unwind_calls.rs b/compiler/rustc_mir_transform/src/ffi_unwind_calls.rs
index c47abb4fcb4..db7dfc5b43e 100644
--- a/compiler/rustc_mir_transform/src/ffi_unwind_calls.rs
+++ b/compiler/rustc_mir_transform/src/ffi_unwind_calls.rs
@@ -26,7 +26,6 @@ fn abi_can_unwind(abi: Abi) -> bool {
         PtxKernel
         | Msp430Interrupt
         | X86Interrupt
-        | AmdGpuKernel
         | EfiApi
         | AvrInterrupt
         | AvrNonBlockingInterrupt
diff --git a/compiler/rustc_passes/src/lang_items.rs b/compiler/rustc_passes/src/lang_items.rs
index 6aeaa8945fb..9a21397789d 100644
--- a/compiler/rustc_passes/src/lang_items.rs
+++ b/compiler/rustc_passes/src/lang_items.rs
@@ -149,7 +149,9 @@ impl<'ast, 'tcx> LanguageItemCollector<'ast, 'tcx> {
                 }
             };
 
-            self.tcx.dcx().emit_err(DuplicateLangItem {
+            // When there's a duplicate lang item, something went very wrong and there's no value in recovering or doing anything.
+            // Give the user the one message to let them debug the mess they created and then wish them farewell.
+            self.tcx.dcx().emit_fatal(DuplicateLangItem {
                 local_span: item_span,
                 lang_item_name,
                 crate_name,
diff --git a/compiler/rustc_pattern_analysis/src/constructor.rs b/compiler/rustc_pattern_analysis/src/constructor.rs
index 4996015f863..4be564b1d7b 100644
--- a/compiler/rustc_pattern_analysis/src/constructor.rs
+++ b/compiler/rustc_pattern_analysis/src/constructor.rs
@@ -163,7 +163,6 @@ use self::MaybeInfiniteInt::*;
 use self::SliceKind::*;
 
 use crate::index;
-use crate::usefulness::PlaceCtxt;
 use crate::TypeCx;
 
 /// Whether we have seen a constructor in the column or not.
@@ -818,8 +817,8 @@ impl<Cx: TypeCx> Constructor<Cx> {
 
     /// The number of fields for this constructor. This must be kept in sync with
     /// `Fields::wildcards`.
-    pub(crate) fn arity(&self, pcx: &PlaceCtxt<'_, Cx>) -> usize {
-        pcx.ctor_arity(self)
+    pub(crate) fn arity(&self, cx: &Cx, ty: &Cx::Ty) -> usize {
+        cx.ctor_arity(self, ty)
     }
 
     /// Returns whether `self` is covered by `other`, i.e. whether `self` is a subset of `other`.
@@ -827,12 +826,11 @@ impl<Cx: TypeCx> Constructor<Cx> {
     /// this checks for inclusion.
     // We inline because this has a single call site in `Matrix::specialize_constructor`.
     #[inline]
-    pub(crate) fn is_covered_by(&self, pcx: &PlaceCtxt<'_, Cx>, other: &Self) -> bool {
+    pub(crate) fn is_covered_by(&self, cx: &Cx, other: &Self) -> bool {
         match (self, other) {
-            (Wildcard, _) => pcx
-                .mcx
-                .tycx
-                .bug(format_args!("Constructor splitting should not have returned `Wildcard`")),
+            (Wildcard, _) => {
+                cx.bug(format_args!("Constructor splitting should not have returned `Wildcard`"))
+            }
             // Wildcards cover anything
             (_, Wildcard) => true,
             // Only a wildcard pattern can match these special constructors.
@@ -873,7 +871,7 @@ impl<Cx: TypeCx> Constructor<Cx> {
             (Opaque(self_id), Opaque(other_id)) => self_id == other_id,
             (Opaque(..), _) | (_, Opaque(..)) => false,
 
-            _ => pcx.mcx.tycx.bug(format_args!(
+            _ => cx.bug(format_args!(
                 "trying to compare incompatible constructors {self:?} and {other:?}"
             )),
         }
@@ -950,10 +948,10 @@ pub enum ConstructorSet<Cx: TypeCx> {
 /// of the `ConstructorSet` for the type, yet if we forgot to include them in `present` we would be
 /// ignoring any row with `Opaque`s in the algorithm. Hence the importance of point 4.
 #[derive(Debug)]
-pub(crate) struct SplitConstructorSet<Cx: TypeCx> {
-    pub(crate) present: SmallVec<[Constructor<Cx>; 1]>,
-    pub(crate) missing: Vec<Constructor<Cx>>,
-    pub(crate) missing_empty: Vec<Constructor<Cx>>,
+pub struct SplitConstructorSet<Cx: TypeCx> {
+    pub present: SmallVec<[Constructor<Cx>; 1]>,
+    pub missing: Vec<Constructor<Cx>>,
+    pub missing_empty: Vec<Constructor<Cx>>,
 }
 
 impl<Cx: TypeCx> ConstructorSet<Cx> {
@@ -962,7 +960,7 @@ impl<Cx: TypeCx> ConstructorSet<Cx> {
     /// or slices. This can get subtle; see [`SplitConstructorSet`] for details of this operation
     /// and its invariants.
     #[instrument(level = "debug", skip(self, ctors), ret)]
-    pub(crate) fn split<'a>(
+    pub fn split<'a>(
         &self,
         ctors: impl Iterator<Item = &'a Constructor<Cx>> + Clone,
     ) -> SplitConstructorSet<Cx>
diff --git a/compiler/rustc_pattern_analysis/src/lib.rs b/compiler/rustc_pattern_analysis/src/lib.rs
index a53d7a0d809..3d0eb117d17 100644
--- a/compiler/rustc_pattern_analysis/src/lib.rs
+++ b/compiler/rustc_pattern_analysis/src/lib.rs
@@ -6,6 +6,7 @@ pub mod errors;
 #[cfg(feature = "rustc")]
 pub(crate) mod lints;
 pub mod pat;
+pub mod pat_column;
 #[cfg(feature = "rustc")]
 pub mod rustc;
 pub mod usefulness;
@@ -67,8 +68,9 @@ use rustc_span::ErrorGuaranteed;
 
 use crate::constructor::{Constructor, ConstructorSet, IntRange};
 #[cfg(feature = "rustc")]
-use crate::lints::{lint_nonexhaustive_missing_variants, PatternColumn};
+use crate::lints::lint_nonexhaustive_missing_variants;
 use crate::pat::DeconstructedPat;
+use crate::pat_column::PatternColumn;
 #[cfg(feature = "rustc")]
 use crate::rustc::RustcMatchCheckCtxt;
 #[cfg(feature = "rustc")]
@@ -135,20 +137,6 @@ pub trait TypeCx: Sized + fmt::Debug {
     }
 }
 
-/// Context that provides information global to a match.
-pub struct MatchCtxt<'a, Cx: TypeCx> {
-    /// The context for type information.
-    pub tycx: &'a Cx,
-}
-
-impl<'a, Cx: TypeCx> Clone for MatchCtxt<'a, Cx> {
-    fn clone(&self) -> Self {
-        Self { tycx: self.tycx }
-    }
-}
-
-impl<'a, Cx: TypeCx> Copy for MatchCtxt<'a, Cx> {}
-
 /// The arm of a match expression.
 #[derive(Debug)]
 pub struct MatchArm<'p, Cx: TypeCx> {
@@ -175,15 +163,13 @@ pub fn analyze_match<'p, 'tcx>(
 ) -> Result<rustc::UsefulnessReport<'p, 'tcx>, ErrorGuaranteed> {
     let scrut_ty = tycx.reveal_opaque_ty(scrut_ty);
     let scrut_validity = ValidityConstraint::from_bool(tycx.known_valid_scrutinee);
-    let cx = MatchCtxt { tycx };
-
-    let report = compute_match_usefulness(cx, arms, scrut_ty, scrut_validity)?;
+    let report = compute_match_usefulness(tycx, arms, scrut_ty, scrut_validity)?;
 
     // Run the non_exhaustive_omitted_patterns lint. Only run on refutable patterns to avoid hitting
     // `if let`s. Only run if the match is exhaustive otherwise the error is redundant.
     if tycx.refutable && report.non_exhaustiveness_witnesses.is_empty() {
         let pat_column = PatternColumn::new(arms);
-        lint_nonexhaustive_missing_variants(cx, arms, &pat_column, scrut_ty)?;
+        lint_nonexhaustive_missing_variants(tycx, arms, &pat_column, scrut_ty)?;
     }
 
     Ok(report)
diff --git a/compiler/rustc_pattern_analysis/src/lints.rs b/compiler/rustc_pattern_analysis/src/lints.rs
index 4bfe7dfb072..3f1497540d2 100644
--- a/compiler/rustc_pattern_analysis/src/lints.rs
+++ b/compiler/rustc_pattern_analysis/src/lints.rs
@@ -1,109 +1,24 @@
 use rustc_session::lint::builtin::NON_EXHAUSTIVE_OMITTED_PATTERNS;
 use rustc_span::ErrorGuaranteed;
 
+use crate::constructor::Constructor;
 use crate::errors::{NonExhaustiveOmittedPattern, NonExhaustiveOmittedPatternLintOnArm, Uncovered};
-use crate::pat::PatOrWild;
-use crate::rustc::{
-    Constructor, DeconstructedPat, MatchArm, MatchCtxt, PlaceCtxt, RevealedTy, RustcMatchCheckCtxt,
-    SplitConstructorSet, WitnessPat,
-};
-
-/// A column of patterns in the matrix, where a column is the intuitive notion of "subpatterns that
-/// inspect the same subvalue/place".
-/// This is used to traverse patterns column-by-column for lints. Despite similarities with the
-/// algorithm in [`crate::usefulness`], this does a different traversal. Notably this is linear in
-/// the depth of patterns, whereas `compute_exhaustiveness_and_usefulness` is worst-case exponential
-/// (exhaustiveness is NP-complete). The core difference is that we treat sub-columns separately.
-///
-/// This must not contain an or-pattern. `expand_and_push` takes care to expand them.
-///
-/// This is not used in the usefulness algorithm; only in lints.
-#[derive(Debug)]
-pub(crate) struct PatternColumn<'p, 'tcx> {
-    patterns: Vec<&'p DeconstructedPat<'p, 'tcx>>,
-}
-
-impl<'p, 'tcx> PatternColumn<'p, 'tcx> {
-    pub(crate) fn new(arms: &[MatchArm<'p, 'tcx>]) -> Self {
-        let patterns = Vec::with_capacity(arms.len());
-        let mut column = PatternColumn { patterns };
-        for arm in arms {
-            column.expand_and_push(PatOrWild::Pat(arm.pat));
-        }
-        column
-    }
-    /// Pushes a pattern onto the column, expanding any or-patterns into its subpatterns.
-    /// Internal method, prefer [`PatternColumn::new`].
-    fn expand_and_push(&mut self, pat: PatOrWild<'p, RustcMatchCheckCtxt<'p, 'tcx>>) {
-        // We flatten or-patterns and skip algorithm-generated wildcards.
-        if pat.is_or_pat() {
-            self.patterns.extend(
-                pat.flatten_or_pat().into_iter().filter_map(|pat_or_wild| pat_or_wild.as_pat()),
-            )
-        } else if let Some(pat) = pat.as_pat() {
-            self.patterns.push(pat)
-        }
-    }
-
-    fn head_ty(&self) -> Option<RevealedTy<'tcx>> {
-        self.patterns.first().map(|pat| *pat.ty())
-    }
-
-    /// Do constructor splitting on the constructors of the column.
-    fn analyze_ctors(
-        &self,
-        pcx: &PlaceCtxt<'_, 'p, 'tcx>,
-    ) -> Result<SplitConstructorSet<'p, 'tcx>, ErrorGuaranteed> {
-        let column_ctors = self.patterns.iter().map(|p| p.ctor());
-        let ctors_for_ty = &pcx.ctors_for_ty()?;
-        Ok(ctors_for_ty.split(column_ctors))
-    }
-
-    /// Does specialization: given a constructor, this takes the patterns from the column that match
-    /// the constructor, and outputs their fields.
-    /// This returns one column per field of the constructor. They usually all have the same length
-    /// (the number of patterns in `self` that matched `ctor`), except that we expand or-patterns
-    /// which may change the lengths.
-    fn specialize(
-        &self,
-        pcx: &PlaceCtxt<'_, 'p, 'tcx>,
-        ctor: &Constructor<'p, 'tcx>,
-    ) -> Vec<PatternColumn<'p, 'tcx>> {
-        let arity = ctor.arity(pcx);
-        if arity == 0 {
-            return Vec::new();
-        }
-
-        // We specialize the column by `ctor`. This gives us `arity`-many columns of patterns. These
-        // columns may have different lengths in the presence of or-patterns (this is why we can't
-        // reuse `Matrix`).
-        let mut specialized_columns: Vec<_> =
-            (0..arity).map(|_| Self { patterns: Vec::new() }).collect();
-        let relevant_patterns =
-            self.patterns.iter().filter(|pat| ctor.is_covered_by(pcx, pat.ctor()));
-        for pat in relevant_patterns {
-            let specialized = pat.specialize(ctor, arity);
-            for (subpat, column) in specialized.into_iter().zip(&mut specialized_columns) {
-                column.expand_and_push(subpat);
-            }
-        }
-        specialized_columns
-    }
-}
+use crate::pat_column::PatternColumn;
+use crate::rustc::{RevealedTy, RustcMatchCheckCtxt, WitnessPat};
+use crate::MatchArm;
 
 /// Traverse the patterns to collect any variants of a non_exhaustive enum that fail to be mentioned
 /// in a given column.
 #[instrument(level = "debug", skip(cx), ret)]
 fn collect_nonexhaustive_missing_variants<'a, 'p, 'tcx>(
-    cx: MatchCtxt<'a, 'p, 'tcx>,
-    column: &PatternColumn<'p, 'tcx>,
+    cx: &RustcMatchCheckCtxt<'p, 'tcx>,
+    column: &PatternColumn<'p, RustcMatchCheckCtxt<'p, 'tcx>>,
 ) -> Result<Vec<WitnessPat<'p, 'tcx>>, ErrorGuaranteed> {
-    let Some(ty) = column.head_ty() else {
+    let Some(&ty) = column.head_ty() else {
         return Ok(Vec::new());
     };
-    let pcx = &PlaceCtxt::new_dummy(cx, &ty);
 
-    let set = column.analyze_ctors(pcx)?;
+    let set = column.analyze_ctors(cx, &ty)?;
     if set.present.is_empty() {
         // We can't consistently handle the case where no constructors are present (since this would
         // require digging deep through any type in case there's a non_exhaustive enum somewhere),
@@ -112,20 +27,20 @@ fn collect_nonexhaustive_missing_variants<'a, 'p, 'tcx>(
     }
 
     let mut witnesses = Vec::new();
-    if cx.tycx.is_foreign_non_exhaustive_enum(ty) {
+    if cx.is_foreign_non_exhaustive_enum(ty) {
         witnesses.extend(
             set.missing
                 .into_iter()
                 // This will list missing visible variants.
                 .filter(|c| !matches!(c, Constructor::Hidden | Constructor::NonExhaustive))
-                .map(|missing_ctor| WitnessPat::wild_from_ctor(pcx, missing_ctor)),
+                .map(|missing_ctor| WitnessPat::wild_from_ctor(cx, missing_ctor, ty)),
         )
     }
 
     // Recurse into the fields.
     for ctor in set.present {
-        let specialized_columns = column.specialize(pcx, &ctor);
-        let wild_pat = WitnessPat::wild_from_ctor(pcx, ctor);
+        let specialized_columns = column.specialize(cx, &ty, &ctor);
+        let wild_pat = WitnessPat::wild_from_ctor(cx, ctor, ty);
         for (i, col_i) in specialized_columns.iter().enumerate() {
             // Compute witnesses for each column.
             let wits_for_col_i = collect_nonexhaustive_missing_variants(cx, col_i)?;
@@ -141,18 +56,17 @@ fn collect_nonexhaustive_missing_variants<'a, 'p, 'tcx>(
     Ok(witnesses)
 }
 
-pub(crate) fn lint_nonexhaustive_missing_variants<'a, 'p, 'tcx>(
-    cx: MatchCtxt<'a, 'p, 'tcx>,
-    arms: &[MatchArm<'p, 'tcx>],
-    pat_column: &PatternColumn<'p, 'tcx>,
+pub(crate) fn lint_nonexhaustive_missing_variants<'p, 'tcx>(
+    rcx: &RustcMatchCheckCtxt<'p, 'tcx>,
+    arms: &[MatchArm<'p, RustcMatchCheckCtxt<'p, 'tcx>>],
+    pat_column: &PatternColumn<'p, RustcMatchCheckCtxt<'p, 'tcx>>,
     scrut_ty: RevealedTy<'tcx>,
 ) -> Result<(), ErrorGuaranteed> {
-    let rcx: &RustcMatchCheckCtxt<'_, '_> = cx.tycx;
     if !matches!(
         rcx.tcx.lint_level_at_node(NON_EXHAUSTIVE_OMITTED_PATTERNS, rcx.match_lint_level).0,
         rustc_session::lint::Level::Allow
     ) {
-        let witnesses = collect_nonexhaustive_missing_variants(cx, pat_column)?;
+        let witnesses = collect_nonexhaustive_missing_variants(rcx, pat_column)?;
         if !witnesses.is_empty() {
             // Report that a match of a `non_exhaustive` enum marked with `non_exhaustive_omitted_patterns`
             // is not exhaustive enough.
diff --git a/compiler/rustc_pattern_analysis/src/pat.rs b/compiler/rustc_pattern_analysis/src/pat.rs
index d476766d466..c94d8b93535 100644
--- a/compiler/rustc_pattern_analysis/src/pat.rs
+++ b/compiler/rustc_pattern_analysis/src/pat.rs
@@ -6,7 +6,6 @@ use std::fmt;
 use smallvec::{smallvec, SmallVec};
 
 use crate::constructor::{Constructor, Slice, SliceKind};
-use crate::usefulness::PlaceCtxt;
 use crate::{Captures, TypeCx};
 
 use self::Constructor::*;
@@ -331,9 +330,9 @@ impl<Cx: TypeCx> WitnessPat<Cx> {
     /// Construct a pattern that matches everything that starts with this constructor.
     /// For example, if `ctor` is a `Constructor::Variant` for `Option::Some`, we get the pattern
     /// `Some(_)`.
-    pub(crate) fn wild_from_ctor(pcx: &PlaceCtxt<'_, Cx>, ctor: Constructor<Cx>) -> Self {
-        let fields = pcx.ctor_sub_tys(&ctor).map(|ty| Self::wildcard(ty)).collect();
-        Self::new(ctor, fields, pcx.ty.clone())
+    pub(crate) fn wild_from_ctor(cx: &Cx, ctor: Constructor<Cx>, ty: Cx::Ty) -> Self {
+        let fields = cx.ctor_sub_tys(&ctor, &ty).map(|ty| Self::wildcard(ty)).collect();
+        Self::new(ctor, fields, ty)
     }
 
     pub fn ctor(&self) -> &Constructor<Cx> {
diff --git a/compiler/rustc_pattern_analysis/src/pat_column.rs b/compiler/rustc_pattern_analysis/src/pat_column.rs
new file mode 100644
index 00000000000..3cacfc491b9
--- /dev/null
+++ b/compiler/rustc_pattern_analysis/src/pat_column.rs
@@ -0,0 +1,90 @@
+use crate::constructor::{Constructor, SplitConstructorSet};
+use crate::pat::{DeconstructedPat, PatOrWild};
+use crate::{Captures, MatchArm, TypeCx};
+
+/// A column of patterns in a match, where a column is the intuitive notion of "subpatterns that
+/// inspect the same subvalue/place".
+/// This is used to traverse patterns column-by-column for lints. Despite similarities with the
+/// algorithm in [`crate::usefulness`], this does a different traversal. Notably this is linear in
+/// the depth of patterns, whereas `compute_exhaustiveness_and_usefulness` is worst-case exponential
+/// (exhaustiveness is NP-complete). The core difference is that we treat sub-columns separately.
+///
+/// This is not used in the usefulness algorithm; only in lints.
+#[derive(Debug)]
+pub struct PatternColumn<'p, Cx: TypeCx> {
+    /// This must not contain an or-pattern. `expand_and_push` takes care to expand them.
+    patterns: Vec<&'p DeconstructedPat<'p, Cx>>,
+}
+
+impl<'p, Cx: TypeCx> PatternColumn<'p, Cx> {
+    pub fn new(arms: &[MatchArm<'p, Cx>]) -> Self {
+        let patterns = Vec::with_capacity(arms.len());
+        let mut column = PatternColumn { patterns };
+        for arm in arms {
+            column.expand_and_push(PatOrWild::Pat(arm.pat));
+        }
+        column
+    }
+    /// Pushes a pattern onto the column, expanding any or-patterns into its subpatterns.
+    /// Internal method, prefer [`PatternColumn::new`].
+    fn expand_and_push(&mut self, pat: PatOrWild<'p, Cx>) {
+        // We flatten or-patterns and skip algorithm-generated wildcards.
+        if pat.is_or_pat() {
+            self.patterns.extend(
+                pat.flatten_or_pat().into_iter().filter_map(|pat_or_wild| pat_or_wild.as_pat()),
+            )
+        } else if let Some(pat) = pat.as_pat() {
+            self.patterns.push(pat)
+        }
+    }
+
+    pub fn head_ty(&self) -> Option<&Cx::Ty> {
+        self.patterns.first().map(|pat| pat.ty())
+    }
+    pub fn iter<'a>(&'a self) -> impl Iterator<Item = &'p DeconstructedPat<'p, Cx>> + Captures<'a> {
+        self.patterns.iter().copied()
+    }
+
+    /// Do constructor splitting on the constructors of the column.
+    pub fn analyze_ctors(
+        &self,
+        cx: &Cx,
+        ty: &Cx::Ty,
+    ) -> Result<SplitConstructorSet<Cx>, Cx::Error> {
+        let column_ctors = self.patterns.iter().map(|p| p.ctor());
+        let ctors_for_ty = cx.ctors_for_ty(ty)?;
+        Ok(ctors_for_ty.split(column_ctors))
+    }
+
+    /// Does specialization: given a constructor, this takes the patterns from the column that match
+    /// the constructor, and outputs their fields.
+    /// This returns one column per field of the constructor. They usually all have the same length
+    /// (the number of patterns in `self` that matched `ctor`), except that we expand or-patterns
+    /// which may change the lengths.
+    pub fn specialize(
+        &self,
+        cx: &Cx,
+        ty: &Cx::Ty,
+        ctor: &Constructor<Cx>,
+    ) -> Vec<PatternColumn<'p, Cx>> {
+        let arity = ctor.arity(cx, ty);
+        if arity == 0 {
+            return Vec::new();
+        }
+
+        // We specialize the column by `ctor`. This gives us `arity`-many columns of patterns. These
+        // columns may have different lengths in the presence of or-patterns (this is why we can't
+        // reuse `Matrix`).
+        let mut specialized_columns: Vec<_> =
+            (0..arity).map(|_| Self { patterns: Vec::new() }).collect();
+        let relevant_patterns =
+            self.patterns.iter().filter(|pat| ctor.is_covered_by(cx, pat.ctor()));
+        for pat in relevant_patterns {
+            let specialized = pat.specialize(ctor, arity);
+            for (subpat, column) in specialized.into_iter().zip(&mut specialized_columns) {
+                column.expand_and_push(subpat);
+            }
+        }
+        specialized_columns
+    }
+}
diff --git a/compiler/rustc_pattern_analysis/src/rustc.rs b/compiler/rustc_pattern_analysis/src/rustc.rs
index 223d6cefc83..ec37e202118 100644
--- a/compiler/rustc_pattern_analysis/src/rustc.rs
+++ b/compiler/rustc_pattern_analysis/src/rustc.rs
@@ -30,11 +30,6 @@ pub type ConstructorSet<'p, 'tcx> =
 pub type DeconstructedPat<'p, 'tcx> =
     crate::pat::DeconstructedPat<'p, RustcMatchCheckCtxt<'p, 'tcx>>;
 pub type MatchArm<'p, 'tcx> = crate::MatchArm<'p, RustcMatchCheckCtxt<'p, 'tcx>>;
-pub type MatchCtxt<'a, 'p, 'tcx> = crate::MatchCtxt<'a, RustcMatchCheckCtxt<'p, 'tcx>>;
-pub(crate) type PlaceCtxt<'a, 'p, 'tcx> =
-    crate::usefulness::PlaceCtxt<'a, RustcMatchCheckCtxt<'p, 'tcx>>;
-pub(crate) type SplitConstructorSet<'p, 'tcx> =
-    crate::constructor::SplitConstructorSet<RustcMatchCheckCtxt<'p, 'tcx>>;
 pub type Usefulness<'p, 'tcx> = crate::usefulness::Usefulness<'p, RustcMatchCheckCtxt<'p, 'tcx>>;
 pub type UsefulnessReport<'p, 'tcx> =
     crate::usefulness::UsefulnessReport<'p, RustcMatchCheckCtxt<'p, 'tcx>>;
diff --git a/compiler/rustc_pattern_analysis/src/usefulness.rs b/compiler/rustc_pattern_analysis/src/usefulness.rs
index b15de1c0ca9..3d45d032a99 100644
--- a/compiler/rustc_pattern_analysis/src/usefulness.rs
+++ b/compiler/rustc_pattern_analysis/src/usefulness.rs
@@ -719,7 +719,7 @@ use std::fmt;
 
 use crate::constructor::{Constructor, ConstructorSet, IntRange};
 use crate::pat::{DeconstructedPat, PatOrWild, WitnessPat};
-use crate::{Captures, MatchArm, MatchCtxt, TypeCx};
+use crate::{Captures, MatchArm, TypeCx};
 
 use self::ValidityConstraint::*;
 
@@ -730,21 +730,33 @@ pub fn ensure_sufficient_stack<R>(f: impl FnOnce() -> R) -> R {
     f()
 }
 
+/// Context that provides information for usefulness checking.
+pub struct UsefulnessCtxt<'a, Cx: TypeCx> {
+    /// The context for type information.
+    pub tycx: &'a Cx,
+}
+
+impl<'a, Cx: TypeCx> Copy for UsefulnessCtxt<'a, Cx> {}
+impl<'a, Cx: TypeCx> Clone for UsefulnessCtxt<'a, Cx> {
+    fn clone(&self) -> Self {
+        Self { tycx: self.tycx }
+    }
+}
+
 /// Context that provides information local to a place under investigation.
-pub(crate) struct PlaceCtxt<'a, Cx: TypeCx> {
-    pub(crate) mcx: MatchCtxt<'a, Cx>,
+struct PlaceCtxt<'a, Cx: TypeCx> {
+    cx: &'a Cx,
     /// Type of the place under investigation.
-    pub(crate) ty: &'a Cx::Ty,
+    ty: &'a Cx::Ty,
 }
 
+impl<'a, Cx: TypeCx> Copy for PlaceCtxt<'a, Cx> {}
 impl<'a, Cx: TypeCx> Clone for PlaceCtxt<'a, Cx> {
     fn clone(&self) -> Self {
-        Self { mcx: self.mcx, ty: self.ty }
+        Self { cx: self.cx, ty: self.ty }
     }
 }
 
-impl<'a, Cx: TypeCx> Copy for PlaceCtxt<'a, Cx> {}
-
 impl<'a, Cx: TypeCx> fmt::Debug for PlaceCtxt<'a, Cx> {
     fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
         fmt.debug_struct("PlaceCtxt").field("ty", self.ty).finish()
@@ -752,23 +764,20 @@ impl<'a, Cx: TypeCx> fmt::Debug for PlaceCtxt<'a, Cx> {
 }
 
 impl<'a, Cx: TypeCx> PlaceCtxt<'a, Cx> {
-    /// A `PlaceCtxt` when code other than `is_useful` needs one.
-    #[cfg_attr(not(feature = "rustc"), allow(dead_code))]
-    pub(crate) fn new_dummy(mcx: MatchCtxt<'a, Cx>, ty: &'a Cx::Ty) -> Self {
-        PlaceCtxt { mcx, ty }
+    fn ctor_arity(&self, ctor: &Constructor<Cx>) -> usize {
+        self.cx.ctor_arity(ctor, self.ty)
     }
-
-    pub(crate) fn ctor_arity(&self, ctor: &Constructor<Cx>) -> usize {
-        self.mcx.tycx.ctor_arity(ctor, self.ty)
-    }
-    pub(crate) fn ctor_sub_tys(
+    fn ctor_sub_tys(
         &'a self,
         ctor: &'a Constructor<Cx>,
     ) -> impl Iterator<Item = Cx::Ty> + ExactSizeIterator + Captures<'a> {
-        self.mcx.tycx.ctor_sub_tys(ctor, self.ty)
+        self.cx.ctor_sub_tys(ctor, self.ty)
+    }
+    fn ctors_for_ty(&self) -> Result<ConstructorSet<Cx>, Cx::Error> {
+        self.cx.ctors_for_ty(self.ty)
     }
-    pub(crate) fn ctors_for_ty(&self) -> Result<ConstructorSet<Cx>, Cx::Error> {
-        self.mcx.tycx.ctors_for_ty(self.ty)
+    fn wild_from_ctor(&self, ctor: Constructor<Cx>) -> WitnessPat<Cx> {
+        WitnessPat::wild_from_ctor(self.cx, ctor, self.ty.clone())
     }
 }
 
@@ -1089,7 +1098,7 @@ impl<'p, Cx: TypeCx> Matrix<'p, Cx> {
             wildcard_row_is_relevant: self.wildcard_row_is_relevant && ctor_is_relevant,
         };
         for (i, row) in self.rows().enumerate() {
-            if ctor.is_covered_by(pcx, row.head().ctor()) {
+            if ctor.is_covered_by(pcx.cx, row.head().ctor()) {
                 let new_row = row.pop_head_constructor(ctor, arity, ctor_is_relevant, i);
                 matrix.expand_and_push(new_row);
             }
@@ -1240,7 +1249,7 @@ impl<Cx: TypeCx> WitnessStack<Cx> {
     /// ```
     fn apply_constructor(&mut self, pcx: &PlaceCtxt<'_, Cx>, ctor: &Constructor<Cx>) {
         let len = self.0.len();
-        let arity = ctor.arity(pcx);
+        let arity = pcx.ctor_arity(ctor);
         let fields = self.0.drain((len - arity)..).rev().collect();
         let pat = WitnessPat::new(ctor.clone(), fields, pcx.ty.clone());
         self.0.push(pat);
@@ -1315,20 +1324,20 @@ impl<Cx: TypeCx> WitnessMatrix<Cx> {
                 *self = Self::empty();
             } else if !report_individual_missing_ctors {
                 // Report `_` as missing.
-                let pat = WitnessPat::wild_from_ctor(pcx, Constructor::Wildcard);
+                let pat = pcx.wild_from_ctor(Constructor::Wildcard);
                 self.push_pattern(pat);
             } else if missing_ctors.iter().any(|c| c.is_non_exhaustive()) {
                 // We need to report a `_` anyway, so listing other constructors would be redundant.
                 // `NonExhaustive` is displayed as `_` just like `Wildcard`, but it will be picked
                 // up by diagnostics to add a note about why `_` is required here.
-                let pat = WitnessPat::wild_from_ctor(pcx, Constructor::NonExhaustive);
+                let pat = pcx.wild_from_ctor(Constructor::NonExhaustive);
                 self.push_pattern(pat);
             } else {
                 // For each missing constructor `c`, we add a `c(_, _, _)` witness appropriately
                 // filled with wildcards.
                 let mut ret = Self::empty();
                 for ctor in missing_ctors {
-                    let pat = WitnessPat::wild_from_ctor(pcx, ctor.clone());
+                    let pat = pcx.wild_from_ctor(ctor.clone());
                     // Clone `self` and add `c(_, _, _)` to each of its witnesses.
                     let mut wit_matrix = self.clone();
                     wit_matrix.push_pattern(pat);
@@ -1362,7 +1371,7 @@ impl<Cx: TypeCx> WitnessMatrix<Cx> {
 /// We can however get false negatives because exhaustiveness does not explore all cases. See the
 /// section on relevancy at the top of the file.
 fn collect_overlapping_range_endpoints<'p, Cx: TypeCx>(
-    mcx: MatchCtxt<'_, Cx>,
+    mcx: UsefulnessCtxt<'_, Cx>,
     overlap_range: IntRange,
     matrix: &Matrix<'p, Cx>,
     specialized_matrix: &Matrix<'p, Cx>,
@@ -1435,7 +1444,7 @@ fn collect_overlapping_range_endpoints<'p, Cx: TypeCx>(
 /// This is all explained at the top of the file.
 #[instrument(level = "debug", skip(mcx, is_top_level), ret)]
 fn compute_exhaustiveness_and_usefulness<'a, 'p, Cx: TypeCx>(
-    mcx: MatchCtxt<'a, Cx>,
+    mcx: UsefulnessCtxt<'a, Cx>,
     matrix: &mut Matrix<'p, Cx>,
     is_top_level: bool,
 ) -> Result<WitnessMatrix<Cx>, Cx::Error> {
@@ -1469,7 +1478,7 @@ fn compute_exhaustiveness_and_usefulness<'a, 'p, Cx: TypeCx>(
     };
 
     debug!("ty: {ty:?}");
-    let pcx = &PlaceCtxt { mcx, ty: &ty };
+    let pcx = &PlaceCtxt { cx: mcx.tycx, ty: &ty };
     let ctors_for_ty = pcx.ctors_for_ty()?;
 
     // Whether the place/column we are inspecting is known to contain valid data.
@@ -1592,13 +1601,14 @@ pub struct UsefulnessReport<'p, Cx: TypeCx> {
 }
 
 /// Computes whether a match is exhaustive and which of its arms are useful.
-#[instrument(skip(cx, arms), level = "debug")]
+#[instrument(skip(tycx, arms), level = "debug")]
 pub fn compute_match_usefulness<'p, Cx: TypeCx>(
-    cx: MatchCtxt<'_, Cx>,
+    tycx: &Cx,
     arms: &[MatchArm<'p, Cx>],
     scrut_ty: Cx::Ty,
     scrut_validity: ValidityConstraint,
 ) -> Result<UsefulnessReport<'p, Cx>, Cx::Error> {
+    let cx = UsefulnessCtxt { tycx };
     let mut matrix = Matrix::new(arms, scrut_ty, scrut_validity);
     let non_exhaustiveness_witnesses =
         compute_exhaustiveness_and_usefulness(cx, &mut matrix, true)?;
diff --git a/compiler/rustc_smir/src/rustc_internal/internal.rs b/compiler/rustc_smir/src/rustc_internal/internal.rs
index fa52f52d60b..6bbfcff5e87 100644
--- a/compiler/rustc_smir/src/rustc_internal/internal.rs
+++ b/compiler/rustc_smir/src/rustc_internal/internal.rs
@@ -449,7 +449,6 @@ impl RustcInternal for Abi {
             Abi::PtxKernel => rustc_target::spec::abi::Abi::PtxKernel,
             Abi::Msp430Interrupt => rustc_target::spec::abi::Abi::Msp430Interrupt,
             Abi::X86Interrupt => rustc_target::spec::abi::Abi::X86Interrupt,
-            Abi::AmdGpuKernel => rustc_target::spec::abi::Abi::AmdGpuKernel,
             Abi::EfiApi => rustc_target::spec::abi::Abi::EfiApi,
             Abi::AvrInterrupt => rustc_target::spec::abi::Abi::AvrInterrupt,
             Abi::AvrNonBlockingInterrupt => rustc_target::spec::abi::Abi::AvrNonBlockingInterrupt,
diff --git a/compiler/rustc_smir/src/rustc_smir/convert/abi.rs b/compiler/rustc_smir/src/rustc_smir/convert/abi.rs
index 68b564741dc..088a836c901 100644
--- a/compiler/rustc_smir/src/rustc_smir/convert/abi.rs
+++ b/compiler/rustc_smir/src/rustc_smir/convert/abi.rs
@@ -111,7 +111,6 @@ impl<'tcx> Stable<'tcx> for rustc_target::abi::call::Conv {
             Conv::X86VectorCall => CallConvention::X86VectorCall,
             Conv::X86_64SysV => CallConvention::X86_64SysV,
             Conv::X86_64Win64 => CallConvention::X86_64Win64,
-            Conv::AmdGpuKernel => CallConvention::AmdGpuKernel,
             Conv::AvrInterrupt => CallConvention::AvrInterrupt,
             Conv::AvrNonBlockingInterrupt => CallConvention::AvrNonBlockingInterrupt,
             Conv::RiscvInterrupt { .. } => CallConvention::RiscvInterrupt,
diff --git a/compiler/rustc_smir/src/rustc_smir/convert/ty.rs b/compiler/rustc_smir/src/rustc_smir/convert/ty.rs
index cffbdc376f1..ba957843bb0 100644
--- a/compiler/rustc_smir/src/rustc_smir/convert/ty.rs
+++ b/compiler/rustc_smir/src/rustc_smir/convert/ty.rs
@@ -223,7 +223,6 @@ impl<'tcx> Stable<'tcx> for ty::FnSig<'tcx> {
                 abi::Abi::PtxKernel => Abi::PtxKernel,
                 abi::Abi::Msp430Interrupt => Abi::Msp430Interrupt,
                 abi::Abi::X86Interrupt => Abi::X86Interrupt,
-                abi::Abi::AmdGpuKernel => Abi::AmdGpuKernel,
                 abi::Abi::EfiApi => Abi::EfiApi,
                 abi::Abi::AvrInterrupt => Abi::AvrInterrupt,
                 abi::Abi::AvrNonBlockingInterrupt => Abi::AvrNonBlockingInterrupt,
diff --git a/compiler/rustc_target/src/abi/call/mod.rs b/compiler/rustc_target/src/abi/call/mod.rs
index 1c83039047e..db721212f8e 100644
--- a/compiler/rustc_target/src/abi/call/mod.rs
+++ b/compiler/rustc_target/src/abi/call/mod.rs
@@ -705,7 +705,6 @@ pub enum Conv {
     X86_64SysV,
     X86_64Win64,
 
-    AmdGpuKernel,
     AvrInterrupt,
     AvrNonBlockingInterrupt,
 
@@ -887,7 +886,6 @@ impl FromStr for Conv {
             "X86VectorCall" => Ok(Conv::X86VectorCall),
             "X86_64SysV" => Ok(Conv::X86_64SysV),
             "X86_64Win64" => Ok(Conv::X86_64Win64),
-            "AmdGpuKernel" => Ok(Conv::AmdGpuKernel),
             "AvrInterrupt" => Ok(Conv::AvrInterrupt),
             "AvrNonBlockingInterrupt" => Ok(Conv::AvrNonBlockingInterrupt),
             "RiscvInterrupt(machine)" => {
diff --git a/compiler/rustc_target/src/json.rs b/compiler/rustc_target/src/json.rs
index c6135149081..f3aecaaab98 100644
--- a/compiler/rustc_target/src/json.rs
+++ b/compiler/rustc_target/src/json.rs
@@ -110,7 +110,6 @@ impl ToJson for crate::abi::call::Conv {
             Self::X86VectorCall => "X86VectorCall",
             Self::X86_64SysV => "X86_64SysV",
             Self::X86_64Win64 => "X86_64Win64",
-            Self::AmdGpuKernel => "AmdGpuKernel",
             Self::AvrInterrupt => "AvrInterrupt",
             Self::AvrNonBlockingInterrupt => "AvrNonBlockingInterrupt",
             Self::RiscvInterrupt { kind } => {
diff --git a/compiler/rustc_target/src/spec/abi/mod.rs b/compiler/rustc_target/src/spec/abi/mod.rs
index 1a0aa6f0c4a..6231787bb9f 100644
--- a/compiler/rustc_target/src/spec/abi/mod.rs
+++ b/compiler/rustc_target/src/spec/abi/mod.rs
@@ -44,7 +44,6 @@ pub enum Abi {
     PtxKernel,
     Msp430Interrupt,
     X86Interrupt,
-    AmdGpuKernel,
     EfiApi,
     AvrInterrupt,
     AvrNonBlockingInterrupt,
@@ -121,7 +120,6 @@ const AbiDatas: &[AbiData] = &[
     AbiData { abi: Abi::PtxKernel, name: "ptx-kernel" },
     AbiData { abi: Abi::Msp430Interrupt, name: "msp430-interrupt" },
     AbiData { abi: Abi::X86Interrupt, name: "x86-interrupt" },
-    AbiData { abi: Abi::AmdGpuKernel, name: "amdgpu-kernel" },
     AbiData { abi: Abi::EfiApi, name: "efiapi" },
     AbiData { abi: Abi::AvrInterrupt, name: "avr-interrupt" },
     AbiData { abi: Abi::AvrNonBlockingInterrupt, name: "avr-non-blocking-interrupt" },
@@ -237,10 +235,6 @@ pub fn is_stable(name: &str) -> Result<(), AbiDisabled> {
             feature: sym::abi_x86_interrupt,
             explain: "x86-interrupt ABI is experimental and subject to change",
         }),
-        "amdgpu-kernel" => Err(AbiDisabled::Unstable {
-            feature: sym::abi_amdgpu_kernel,
-            explain: "amdgpu-kernel ABI is experimental and subject to change",
-        }),
         "avr-interrupt" | "avr-non-blocking-interrupt" => Err(AbiDisabled::Unstable {
             feature: sym::abi_avr_interrupt,
             explain: "avr-interrupt and avr-non-blocking-interrupt ABIs are experimental and subject to change",
@@ -295,22 +289,21 @@ impl Abi {
             PtxKernel => 19,
             Msp430Interrupt => 20,
             X86Interrupt => 21,
-            AmdGpuKernel => 22,
-            EfiApi => 23,
-            AvrInterrupt => 24,
-            AvrNonBlockingInterrupt => 25,
-            CCmseNonSecureCall => 26,
-            Wasm => 27,
+            EfiApi => 22,
+            AvrInterrupt => 23,
+            AvrNonBlockingInterrupt => 24,
+            CCmseNonSecureCall => 25,
+            Wasm => 26,
             // Cross-platform ABIs
-            System { unwind: false } => 28,
-            System { unwind: true } => 29,
-            RustIntrinsic => 30,
-            RustCall => 31,
-            PlatformIntrinsic => 32,
-            Unadjusted => 33,
-            RustCold => 34,
-            RiscvInterruptM => 35,
-            RiscvInterruptS => 36,
+            System { unwind: false } => 27,
+            System { unwind: true } => 28,
+            RustIntrinsic => 29,
+            RustCall => 30,
+            PlatformIntrinsic => 31,
+            Unadjusted => 32,
+            RustCold => 33,
+            RiscvInterruptM => 34,
+            RiscvInterruptS => 35,
         };
         debug_assert!(
             AbiDatas
diff --git a/compiler/rustc_target/src/spec/mod.rs b/compiler/rustc_target/src/spec/mod.rs
index 884bd23e8cc..6c698c5b01d 100644
--- a/compiler/rustc_target/src/spec/mod.rs
+++ b/compiler/rustc_target/src/spec/mod.rs
@@ -2457,7 +2457,6 @@ impl Target {
             Win64 { .. } | SysV64 { .. } => self.arch == "x86_64",
             PtxKernel => self.arch == "nvptx64",
             Msp430Interrupt => self.arch == "msp430",
-            AmdGpuKernel => self.arch == "amdgcn",
             RiscvInterruptM | RiscvInterruptS => ["riscv32", "riscv64"].contains(&&self.arch[..]),
             AvrInterrupt | AvrNonBlockingInterrupt => self.arch == "avr",
             Wasm => ["wasm32", "wasm64"].contains(&&self.arch[..]),
diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
index 69649e36178..5bab57ca56c 100644
--- a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
+++ b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
@@ -1432,20 +1432,18 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
     ) -> bool {
         let span = obligation.cause.span;
 
-        let code = if let ObligationCauseCode::FunctionArgumentObligation { parent_code, .. } =
-            obligation.cause.code()
-        {
-            parent_code
-        } else if let ObligationCauseCode::ItemObligation(_)
-        | ObligationCauseCode::ExprItemObligation(..) = obligation.cause.code()
-        {
-            obligation.cause.code()
-        } else if let ExpnKind::Desugaring(DesugaringKind::ForLoop) =
-            span.ctxt().outer_expn_data().kind
-        {
-            obligation.cause.code()
-        } else {
-            return false;
+        let code = match obligation.cause.code() {
+            ObligationCauseCode::FunctionArgumentObligation { parent_code, .. } => parent_code,
+            c @ ObligationCauseCode::ItemObligation(_)
+            | c @ ObligationCauseCode::ExprItemObligation(..) => c,
+            c if matches!(
+                span.ctxt().outer_expn_data().kind,
+                ExpnKind::Desugaring(DesugaringKind::ForLoop)
+            ) =>
+            {
+                c
+            }
+            _ => return false,
         };
 
         // List of traits for which it would be nonsensical to suggest borrowing.
@@ -4978,16 +4976,27 @@ pub(super) fn get_explanation_based_on_obligation<'tcx>(
             _ => None,
         };
 
+        let pred = obligation.predicate;
+        let (_, base) = obligation.cause.code().peel_derives_with_predicate();
+        let post = if let ty::PredicateKind::Clause(clause) = pred.kind().skip_binder()
+            && let ty::ClauseKind::Trait(pred) = clause
+            && let Some(base) = base
+            && base.skip_binder() != pred
+        {
+            format!(", which is required by `{base}`")
+        } else {
+            String::new()
+        };
         match ty_desc {
             Some(desc) => format!(
-                "{}the trait `{}` is not implemented for {} `{}`",
+                "{}the trait `{}` is not implemented for {} `{}`{post}",
                 pre_message,
                 trait_predicate.print_modifiers_and_trait_path(),
                 desc,
                 tcx.short_ty_string(trait_ref.skip_binder().self_ty(), &mut None),
             ),
             None => format!(
-                "{}the trait `{}` is not implemented for `{}`",
+                "{}the trait `{}` is not implemented for `{}`{post}",
                 pre_message,
                 trait_predicate.print_modifiers_and_trait_path(),
                 tcx.short_ty_string(trait_ref.skip_binder().self_ty(), &mut None),
diff --git a/compiler/rustc_ty_utils/src/abi.rs b/compiler/rustc_ty_utils/src/abi.rs
index 333aec1d38d..af26616831f 100644
--- a/compiler/rustc_ty_utils/src/abi.rs
+++ b/compiler/rustc_ty_utils/src/abi.rs
@@ -258,7 +258,6 @@ fn conv_from_spec_abi(tcx: TyCtxt<'_>, abi: SpecAbi, c_variadic: bool) -> Conv {
         PtxKernel => Conv::PtxKernel,
         Msp430Interrupt => Conv::Msp430Intr,
         X86Interrupt => Conv::X86Intr,
-        AmdGpuKernel => Conv::AmdGpuKernel,
         AvrInterrupt => Conv::AvrInterrupt,
         AvrNonBlockingInterrupt => Conv::AvrNonBlockingInterrupt,
         RiscvInterruptM => Conv::RiscvInterrupt { kind: RiscvInterruptKind::Machine },
diff --git a/compiler/stable_mir/src/abi.rs b/compiler/stable_mir/src/abi.rs
index 53dac6abefb..a15fd3e0999 100644
--- a/compiler/stable_mir/src/abi.rs
+++ b/compiler/stable_mir/src/abi.rs
@@ -275,7 +275,6 @@ pub enum CallConvention {
     X86_64SysV,
     X86_64Win64,
 
-    AmdGpuKernel,
     AvrInterrupt,
     AvrNonBlockingInterrupt,
 
diff --git a/compiler/stable_mir/src/ty.rs b/compiler/stable_mir/src/ty.rs
index b0a08cd9b79..bdda9295347 100644
--- a/compiler/stable_mir/src/ty.rs
+++ b/compiler/stable_mir/src/ty.rs
@@ -864,7 +864,6 @@ pub enum Abi {
     PtxKernel,
     Msp430Interrupt,
     X86Interrupt,
-    AmdGpuKernel,
     EfiApi,
     AvrInterrupt,
     AvrNonBlockingInterrupt,
diff --git a/library/alloc/src/vec/mod.rs b/library/alloc/src/vec/mod.rs
index a360c430946..b3e5ecc9240 100644
--- a/library/alloc/src/vec/mod.rs
+++ b/library/alloc/src/vec/mod.rs
@@ -2784,6 +2784,50 @@ impl<T, I: SliceIndex<[T]>, A: Allocator> IndexMut<I> for Vec<T, A> {
     }
 }
 
+/// Collects an iterator into a Vec, commonly called via [`Iterator::collect()`]
+///
+/// # Allocation behavior
+///
+/// In general `Vec` does not guarantee any particular growth or allocation strategy.
+/// That also applies to this trait impl.
+///
+/// **Note:** This section covers implementation details and is therefore exempt from
+/// stability guarantees.
+///
+/// Vec may use any or none of the following strategies,
+/// depending on the supplied iterator:
+///
+/// * preallocate based on [`Iterator::size_hint()`]
+///   * and panic if the number of items is outside the provided lower/upper bounds
+/// * use an amortized growth strategy similar to `pushing` one item at a time
+/// * perform the iteration in-place on the original allocation backing the iterator
+///
+/// The last case warrants some attention. It is an optimization that in many cases reduces peak memory
+/// consumption and improves cache locality. But when big, short-lived allocations are created,
+/// only a small fraction of their items get collected, no further use is made of the spare capacity
+/// and the resulting `Vec` is moved into a longer-lived structure, then this can lead to the large
+/// allocations having their lifetimes unnecessarily extended which can result in increased memory
+/// footprint.
+///
+/// In cases where this is an issue, the excess capacity can be discarded with [`Vec::shrink_to()`],
+/// [`Vec::shrink_to_fit()`] or by collecting into [`Box<[T]>`][owned slice] instead, which additionally reduces
+/// the size of the long-lived struct.
+///
+/// [owned slice]: Box
+///
+/// ```rust
+/// # use std::sync::Mutex;
+/// static LONG_LIVED: Mutex<Vec<Vec<u16>>> = Mutex::new(Vec::new());
+///
+/// for i in 0..10 {
+///     let big_temporary: Vec<u16> = (0..1024).collect();
+///     // discard most items
+///     let mut result: Vec<_> = big_temporary.into_iter().filter(|i| i % 100 == 0).collect();
+///     // without this a lot of unused capacity might be moved into the global
+///     result.shrink_to_fit();
+///     LONG_LIVED.lock().unwrap().push(result);
+/// }
+/// ```
 #[cfg(not(no_global_oom_handling))]
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<T> FromIterator<T> for Vec<T> {
diff --git a/library/std/src/sys/pal/unix/thread_local_dtor.rs b/library/std/src/sys/pal/unix/thread_local_dtor.rs
index 7e19e6eb9eb..4bf8f20670d 100644
--- a/library/std/src/sys/pal/unix/thread_local_dtor.rs
+++ b/library/std/src/sys/pal/unix/thread_local_dtor.rs
@@ -18,7 +18,6 @@
     target_os = "fuchsia",
     target_os = "redox",
     target_os = "hurd",
-    target_os = "freebsd",
     target_os = "netbsd",
     target_os = "dragonfly"
 ))]
@@ -118,7 +117,8 @@ pub unsafe fn register_dtor(t: *mut u8, dtor: unsafe extern "C" fn(*mut u8)) {
     target_os = "vxworks",
     target_os = "horizon",
     target_os = "emscripten",
-    target_os = "aix"
+    target_os = "aix",
+    target_os = "freebsd",
 ))]
 #[cfg_attr(target_family = "wasm", allow(unused))] // might remain unused depending on target details (e.g. wasm32-unknown-emscripten)
 pub unsafe fn register_dtor(t: *mut u8, dtor: unsafe extern "C" fn(*mut u8)) {
diff --git a/src/bootstrap/src/core/config/tests.rs b/src/bootstrap/src/core/config/tests.rs
index 201d11571c4..0ae466eca7d 100644
--- a/src/bootstrap/src/core/config/tests.rs
+++ b/src/bootstrap/src/core/config/tests.rs
@@ -174,12 +174,14 @@ fn override_toml_duplicate() {
 #[test]
 fn profile_user_dist() {
     fn get_toml(file: &Path) -> TomlConfig {
-        let contents = if file.ends_with("config.toml") {
-            "profile = \"user\"".to_owned()
-        } else {
-            assert!(file.ends_with("config.dist.toml"));
-            std::fs::read_to_string(file).unwrap()
-        };
+        let contents =
+            if file.ends_with("config.toml") || env::var_os("RUST_BOOTSTRAP_CONFIG").is_some() {
+                "profile = \"user\"".to_owned()
+            } else {
+                assert!(file.ends_with("config.dist.toml"));
+                std::fs::read_to_string(file).unwrap()
+            };
+
         toml::from_str(&contents)
             .and_then(|table: toml::Value| TomlConfig::deserialize(table))
             .unwrap()
diff --git a/src/librustdoc/clean/mod.rs b/src/librustdoc/clean/mod.rs
index 1e718c70c3c..bd1d68e7074 100644
--- a/src/librustdoc/clean/mod.rs
+++ b/src/librustdoc/clean/mod.rs
@@ -148,6 +148,17 @@ pub(crate) fn clean_doc_module<'tcx>(doc: &DocModule<'tcx>, cx: &mut DocContext<
     )
 }
 
+fn is_glob_import(tcx: TyCtxt<'_>, import_id: LocalDefId) -> bool {
+    if let Some(node) = tcx.opt_hir_node_by_def_id(import_id)
+        && let hir::Node::Item(item) = node
+        && let hir::ItemKind::Use(_, use_kind) = item.kind
+    {
+        use_kind == hir::UseKind::Glob
+    } else {
+        false
+    }
+}
+
 fn generate_item_with_correct_attrs(
     cx: &mut DocContext<'_>,
     kind: ItemKind,
@@ -158,10 +169,17 @@ fn generate_item_with_correct_attrs(
 ) -> Item {
     let target_attrs = inline::load_attrs(cx, def_id);
     let attrs = if let Some(import_id) = import_id {
+        // glob reexports are treated the same as `#[doc(inline)]` items.
+        //
+        // For glob re-exports the item may or may not exist to be re-exported (potentially the cfgs
+        // on the path up until the glob can be removed, and only cfgs on the globbed item itself
+        // matter), for non-inlined re-exports see #85043.
         let is_inline = inline::load_attrs(cx, import_id.to_def_id())
             .lists(sym::doc)
             .get_word_attr(sym::inline)
-            .is_some();
+            .is_some()
+            || (is_glob_import(cx.tcx, import_id)
+                && (cx.render_options.document_hidden || !cx.tcx.is_doc_hidden(def_id)));
         let mut attrs = get_all_import_attributes(cx, import_id, def_id, is_inline);
         add_without_unwanted_attributes(&mut attrs, target_attrs, is_inline, None);
         attrs
diff --git a/src/tools/clippy/tests/ui/same_name_method.rs b/src/tools/clippy/tests/ui/same_name_method.rs
index 1c166a19b0a..26b1a299ba1 100644
--- a/src/tools/clippy/tests/ui/same_name_method.rs
+++ b/src/tools/clippy/tests/ui/same_name_method.rs
@@ -74,6 +74,7 @@ mod should_lint {
         impl S {
             fn foo() {}
             //~^ ERROR: method's name is the same as an existing method in a trait
+            //~| ERROR: method's name is the same as an existing method in a trait
         }
 
         impl T1 for S {}
diff --git a/src/tools/clippy/tests/ui/same_name_method.stderr b/src/tools/clippy/tests/ui/same_name_method.stderr
index 3c5c4a53ad1..82f5ef6a9e8 100644
--- a/src/tools/clippy/tests/ui/same_name_method.stderr
+++ b/src/tools/clippy/tests/ui/same_name_method.stderr
@@ -56,10 +56,22 @@ LL |             fn foo() {}
    |             ^^^^^^^^^^^
    |
 note: existing `foo` defined here
-  --> $DIR/same_name_method.rs:79:9
+  --> $DIR/same_name_method.rs:80:9
    |
 LL |         impl T1 for S {}
    |         ^^^^^^^^^^^^^^^^
 
-error: aborting due to 5 previous errors
+error: method's name is the same as an existing method in a trait
+  --> $DIR/same_name_method.rs:75:13
+   |
+LL |             fn foo() {}
+   |             ^^^^^^^^^^^
+   |
+note: existing `foo` defined here
+  --> $DIR/same_name_method.rs:82:9
+   |
+LL |         impl T2 for S {}
+   |         ^^^^^^^^^^^^^^^^
+
+error: aborting due to 6 previous errors
 
diff --git a/tests/rustdoc-ui/unescaped_backticks.stderr b/tests/rustdoc-ui/unescaped_backticks.stderr
index bd21dcb6e1a..000a5b597d2 100644
--- a/tests/rustdoc-ui/unescaped_backticks.stderr
+++ b/tests/rustdoc-ui/unescaped_backticks.stderr
@@ -302,7 +302,6 @@ LL | |     /// level changes.
    = help: if you meant to use a literal backtick, escape it
             change: or `None` if it isn't.
            to this: or `None\` if it isn't.
-   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
 
 error: unescaped backtick
   --> $DIR/unescaped_backticks.rs:323:5
@@ -322,7 +321,6 @@ LL | |     /// level changes.
    = help: if you meant to use a literal backtick, escape it
             change: `on_event` should be called.
            to this: `on_event\` should be called.
-   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
 
 error: unescaped backtick
   --> $DIR/unescaped_backticks.rs:323:5
@@ -342,7 +340,6 @@ LL | |     /// level changes.
    = help: if you meant to use a literal backtick, escape it
             change: [`rebuild_interest_cache`][rebuild] is called after the value of the max
            to this: [`rebuild_interest_cache\`][rebuild] is called after the value of the max
-   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
 
 error: unescaped backtick
   --> $DIR/unescaped_backticks.rs:349:56
diff --git a/tests/rustdoc/glob-reexport-attribute-merge-120487.rs b/tests/rustdoc/glob-reexport-attribute-merge-120487.rs
new file mode 100644
index 00000000000..98cdec107ae
--- /dev/null
+++ b/tests/rustdoc/glob-reexport-attribute-merge-120487.rs
@@ -0,0 +1,32 @@
+// This test ensures that non-glob reexports don't get their attributes merge with
+// the reexported item whereas glob reexports do.
+// Regression test for <https://github.com/rust-lang/rust/issues/120487>.
+
+#![crate_name = "foo"]
+#![feature(doc_cfg)]
+
+// @has 'foo/index.html'
+// There are two items.
+// @count - '//*[@class="item-table"]//div[@class="item-name"]' 2
+// Only one of them should have an attribute.
+// @count - '//*[@class="item-table"]//div[@class="item-name"]/*[@class="stab portability"]' 1
+
+mod a {
+    #[doc(cfg(not(feature = "a")))]
+    #[cfg(not(feature = "a"))]
+    pub struct Test1;
+}
+
+mod b {
+    #[doc(cfg(not(feature = "a")))]
+    #[cfg(not(feature = "a"))]
+    pub struct Test2;
+}
+
+// @has 'foo/struct.Test1.html'
+// @count - '//*[@id="main-content"]/*[@class="item-info"]' 1
+// @has - '//*[@id="main-content"]/*[@class="item-info"]' 'Available on non-crate feature a only.'
+pub use a::*;
+// @has 'foo/struct.Test2.html'
+// @count - '//*[@id="main-content"]/*[@class="item-info"]' 0
+pub use b::Test2;
diff --git a/tests/ui/abi/unsupported.aarch64.stderr b/tests/ui/abi/unsupported.aarch64.stderr
index d7b4e6150ff..72a9519e3e7 100644
--- a/tests/ui/abi/unsupported.aarch64.stderr
+++ b/tests/ui/abi/unsupported.aarch64.stderr
@@ -1,59 +1,53 @@
 error[E0570]: `"ptx-kernel"` is not a supported ABI for the current target
-  --> $DIR/unsupported.rs:30:1
+  --> $DIR/unsupported.rs:29:1
    |
 LL | extern "ptx-kernel" fn ptx() {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error[E0570]: `"amdgpu-kernel"` is not a supported ABI for the current target
-  --> $DIR/unsupported.rs:32:1
-   |
-LL | extern "amdgpu-kernel" fn amdgpu() {}
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
 error[E0570]: `"wasm"` is not a supported ABI for the current target
-  --> $DIR/unsupported.rs:34:1
+  --> $DIR/unsupported.rs:31:1
    |
 LL | extern "wasm" fn wasm() {}
    | ^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0570]: `"aapcs"` is not a supported ABI for the current target
-  --> $DIR/unsupported.rs:36:1
+  --> $DIR/unsupported.rs:33:1
    |
 LL | extern "aapcs" fn aapcs() {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0570]: `"msp430-interrupt"` is not a supported ABI for the current target
-  --> $DIR/unsupported.rs:42:1
+  --> $DIR/unsupported.rs:39:1
    |
 LL | extern "msp430-interrupt" fn msp430() {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0570]: `"avr-interrupt"` is not a supported ABI for the current target
-  --> $DIR/unsupported.rs:44:1
+  --> $DIR/unsupported.rs:41:1
    |
 LL | extern "avr-interrupt" fn avr() {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0570]: `"riscv-interrupt-m"` is not a supported ABI for the current target
-  --> $DIR/unsupported.rs:46:1
+  --> $DIR/unsupported.rs:43:1
    |
 LL | extern "riscv-interrupt-m" fn riscv() {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0570]: `"x86-interrupt"` is not a supported ABI for the current target
-  --> $DIR/unsupported.rs:51:1
+  --> $DIR/unsupported.rs:48:1
    |
 LL | extern "x86-interrupt" fn x86() {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0570]: `"thiscall"` is not a supported ABI for the current target
-  --> $DIR/unsupported.rs:56:1
+  --> $DIR/unsupported.rs:53:1
    |
 LL | extern "thiscall" fn thiscall() {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: use of calling convention not supported on this target
-  --> $DIR/unsupported.rs:62:1
+  --> $DIR/unsupported.rs:59:1
    |
 LL | extern "stdcall" fn stdcall() {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -62,6 +56,6 @@ LL | extern "stdcall" fn stdcall() {}
    = note: for more information, see issue #87678 <https://github.com/rust-lang/rust/issues/87678>
    = note: `#[warn(unsupported_calling_conventions)]` on by default
 
-error: aborting due to 9 previous errors; 1 warning emitted
+error: aborting due to 8 previous errors; 1 warning emitted
 
 For more information about this error, try `rustc --explain E0570`.
diff --git a/tests/ui/abi/unsupported.arm.stderr b/tests/ui/abi/unsupported.arm.stderr
index 3a3ed2dd9c5..473b59a334d 100644
--- a/tests/ui/abi/unsupported.arm.stderr
+++ b/tests/ui/abi/unsupported.arm.stderr
@@ -1,53 +1,47 @@
 error[E0570]: `"ptx-kernel"` is not a supported ABI for the current target
-  --> $DIR/unsupported.rs:30:1
+  --> $DIR/unsupported.rs:29:1
    |
 LL | extern "ptx-kernel" fn ptx() {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error[E0570]: `"amdgpu-kernel"` is not a supported ABI for the current target
-  --> $DIR/unsupported.rs:32:1
-   |
-LL | extern "amdgpu-kernel" fn amdgpu() {}
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
 error[E0570]: `"wasm"` is not a supported ABI for the current target
-  --> $DIR/unsupported.rs:34:1
+  --> $DIR/unsupported.rs:31:1
    |
 LL | extern "wasm" fn wasm() {}
    | ^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0570]: `"msp430-interrupt"` is not a supported ABI for the current target
-  --> $DIR/unsupported.rs:42:1
+  --> $DIR/unsupported.rs:39:1
    |
 LL | extern "msp430-interrupt" fn msp430() {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0570]: `"avr-interrupt"` is not a supported ABI for the current target
-  --> $DIR/unsupported.rs:44:1
+  --> $DIR/unsupported.rs:41:1
    |
 LL | extern "avr-interrupt" fn avr() {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0570]: `"riscv-interrupt-m"` is not a supported ABI for the current target
-  --> $DIR/unsupported.rs:46:1
+  --> $DIR/unsupported.rs:43:1
    |
 LL | extern "riscv-interrupt-m" fn riscv() {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0570]: `"x86-interrupt"` is not a supported ABI for the current target
-  --> $DIR/unsupported.rs:51:1
+  --> $DIR/unsupported.rs:48:1
    |
 LL | extern "x86-interrupt" fn x86() {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0570]: `"thiscall"` is not a supported ABI for the current target
-  --> $DIR/unsupported.rs:56:1
+  --> $DIR/unsupported.rs:53:1
    |
 LL | extern "thiscall" fn thiscall() {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: use of calling convention not supported on this target
-  --> $DIR/unsupported.rs:62:1
+  --> $DIR/unsupported.rs:59:1
    |
 LL | extern "stdcall" fn stdcall() {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -56,6 +50,6 @@ LL | extern "stdcall" fn stdcall() {}
    = note: for more information, see issue #87678 <https://github.com/rust-lang/rust/issues/87678>
    = note: `#[warn(unsupported_calling_conventions)]` on by default
 
-error: aborting due to 8 previous errors; 1 warning emitted
+error: aborting due to 7 previous errors; 1 warning emitted
 
 For more information about this error, try `rustc --explain E0570`.
diff --git a/tests/ui/abi/unsupported.i686.stderr b/tests/ui/abi/unsupported.i686.stderr
index 31b7d030bd3..f0af3d251e2 100644
--- a/tests/ui/abi/unsupported.i686.stderr
+++ b/tests/ui/abi/unsupported.i686.stderr
@@ -1,45 +1,39 @@
 error[E0570]: `"ptx-kernel"` is not a supported ABI for the current target
-  --> $DIR/unsupported.rs:30:1
+  --> $DIR/unsupported.rs:29:1
    |
 LL | extern "ptx-kernel" fn ptx() {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error[E0570]: `"amdgpu-kernel"` is not a supported ABI for the current target
-  --> $DIR/unsupported.rs:32:1
-   |
-LL | extern "amdgpu-kernel" fn amdgpu() {}
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
 error[E0570]: `"wasm"` is not a supported ABI for the current target
-  --> $DIR/unsupported.rs:34:1
+  --> $DIR/unsupported.rs:31:1
    |
 LL | extern "wasm" fn wasm() {}
    | ^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0570]: `"aapcs"` is not a supported ABI for the current target
-  --> $DIR/unsupported.rs:36:1
+  --> $DIR/unsupported.rs:33:1
    |
 LL | extern "aapcs" fn aapcs() {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0570]: `"msp430-interrupt"` is not a supported ABI for the current target
-  --> $DIR/unsupported.rs:42:1
+  --> $DIR/unsupported.rs:39:1
    |
 LL | extern "msp430-interrupt" fn msp430() {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0570]: `"avr-interrupt"` is not a supported ABI for the current target
-  --> $DIR/unsupported.rs:44:1
+  --> $DIR/unsupported.rs:41:1
    |
 LL | extern "avr-interrupt" fn avr() {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0570]: `"riscv-interrupt-m"` is not a supported ABI for the current target
-  --> $DIR/unsupported.rs:46:1
+  --> $DIR/unsupported.rs:43:1
    |
 LL | extern "riscv-interrupt-m" fn riscv() {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: aborting due to 7 previous errors
+error: aborting due to 6 previous errors
 
 For more information about this error, try `rustc --explain E0570`.
diff --git a/tests/ui/abi/unsupported.riscv32.stderr b/tests/ui/abi/unsupported.riscv32.stderr
index 1966e18f0a0..b466a2a6ff8 100644
--- a/tests/ui/abi/unsupported.riscv32.stderr
+++ b/tests/ui/abi/unsupported.riscv32.stderr
@@ -1,53 +1,47 @@
 error[E0570]: `"ptx-kernel"` is not a supported ABI for the current target
-  --> $DIR/unsupported.rs:30:1
+  --> $DIR/unsupported.rs:29:1
    |
 LL | extern "ptx-kernel" fn ptx() {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error[E0570]: `"amdgpu-kernel"` is not a supported ABI for the current target
-  --> $DIR/unsupported.rs:32:1
-   |
-LL | extern "amdgpu-kernel" fn amdgpu() {}
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
 error[E0570]: `"wasm"` is not a supported ABI for the current target
-  --> $DIR/unsupported.rs:34:1
+  --> $DIR/unsupported.rs:31:1
    |
 LL | extern "wasm" fn wasm() {}
    | ^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0570]: `"aapcs"` is not a supported ABI for the current target
-  --> $DIR/unsupported.rs:36:1
+  --> $DIR/unsupported.rs:33:1
    |
 LL | extern "aapcs" fn aapcs() {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0570]: `"msp430-interrupt"` is not a supported ABI for the current target
-  --> $DIR/unsupported.rs:42:1
+  --> $DIR/unsupported.rs:39:1
    |
 LL | extern "msp430-interrupt" fn msp430() {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0570]: `"avr-interrupt"` is not a supported ABI for the current target
-  --> $DIR/unsupported.rs:44:1
+  --> $DIR/unsupported.rs:41:1
    |
 LL | extern "avr-interrupt" fn avr() {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0570]: `"x86-interrupt"` is not a supported ABI for the current target
-  --> $DIR/unsupported.rs:51:1
+  --> $DIR/unsupported.rs:48:1
    |
 LL | extern "x86-interrupt" fn x86() {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0570]: `"thiscall"` is not a supported ABI for the current target
-  --> $DIR/unsupported.rs:56:1
+  --> $DIR/unsupported.rs:53:1
    |
 LL | extern "thiscall" fn thiscall() {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: use of calling convention not supported on this target
-  --> $DIR/unsupported.rs:62:1
+  --> $DIR/unsupported.rs:59:1
    |
 LL | extern "stdcall" fn stdcall() {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -56,6 +50,6 @@ LL | extern "stdcall" fn stdcall() {}
    = note: for more information, see issue #87678 <https://github.com/rust-lang/rust/issues/87678>
    = note: `#[warn(unsupported_calling_conventions)]` on by default
 
-error: aborting due to 8 previous errors; 1 warning emitted
+error: aborting due to 7 previous errors; 1 warning emitted
 
 For more information about this error, try `rustc --explain E0570`.
diff --git a/tests/ui/abi/unsupported.riscv64.stderr b/tests/ui/abi/unsupported.riscv64.stderr
index 1966e18f0a0..b466a2a6ff8 100644
--- a/tests/ui/abi/unsupported.riscv64.stderr
+++ b/tests/ui/abi/unsupported.riscv64.stderr
@@ -1,53 +1,47 @@
 error[E0570]: `"ptx-kernel"` is not a supported ABI for the current target
-  --> $DIR/unsupported.rs:30:1
+  --> $DIR/unsupported.rs:29:1
    |
 LL | extern "ptx-kernel" fn ptx() {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error[E0570]: `"amdgpu-kernel"` is not a supported ABI for the current target
-  --> $DIR/unsupported.rs:32:1
-   |
-LL | extern "amdgpu-kernel" fn amdgpu() {}
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
 error[E0570]: `"wasm"` is not a supported ABI for the current target
-  --> $DIR/unsupported.rs:34:1
+  --> $DIR/unsupported.rs:31:1
    |
 LL | extern "wasm" fn wasm() {}
    | ^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0570]: `"aapcs"` is not a supported ABI for the current target
-  --> $DIR/unsupported.rs:36:1
+  --> $DIR/unsupported.rs:33:1
    |
 LL | extern "aapcs" fn aapcs() {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0570]: `"msp430-interrupt"` is not a supported ABI for the current target
-  --> $DIR/unsupported.rs:42:1
+  --> $DIR/unsupported.rs:39:1
    |
 LL | extern "msp430-interrupt" fn msp430() {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0570]: `"avr-interrupt"` is not a supported ABI for the current target
-  --> $DIR/unsupported.rs:44:1
+  --> $DIR/unsupported.rs:41:1
    |
 LL | extern "avr-interrupt" fn avr() {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0570]: `"x86-interrupt"` is not a supported ABI for the current target
-  --> $DIR/unsupported.rs:51:1
+  --> $DIR/unsupported.rs:48:1
    |
 LL | extern "x86-interrupt" fn x86() {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0570]: `"thiscall"` is not a supported ABI for the current target
-  --> $DIR/unsupported.rs:56:1
+  --> $DIR/unsupported.rs:53:1
    |
 LL | extern "thiscall" fn thiscall() {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: use of calling convention not supported on this target
-  --> $DIR/unsupported.rs:62:1
+  --> $DIR/unsupported.rs:59:1
    |
 LL | extern "stdcall" fn stdcall() {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -56,6 +50,6 @@ LL | extern "stdcall" fn stdcall() {}
    = note: for more information, see issue #87678 <https://github.com/rust-lang/rust/issues/87678>
    = note: `#[warn(unsupported_calling_conventions)]` on by default
 
-error: aborting due to 8 previous errors; 1 warning emitted
+error: aborting due to 7 previous errors; 1 warning emitted
 
 For more information about this error, try `rustc --explain E0570`.
diff --git a/tests/ui/abi/unsupported.rs b/tests/ui/abi/unsupported.rs
index 57278e664b5..9b99e51905d 100644
--- a/tests/ui/abi/unsupported.rs
+++ b/tests/ui/abi/unsupported.rs
@@ -19,7 +19,6 @@
     abi_ptx,
     abi_msp430_interrupt,
     abi_avr_interrupt,
-    abi_amdgpu_kernel,
     wasm_abi,
     abi_x86_interrupt,
     abi_riscv_interrupt
@@ -29,8 +28,6 @@ trait Sized {}
 
 extern "ptx-kernel" fn ptx() {}
 //~^ ERROR is not a supported ABI
-extern "amdgpu-kernel" fn amdgpu() {}
-//~^ ERROR is not a supported ABI
 extern "wasm" fn wasm() {}
 //~^ ERROR is not a supported ABI
 extern "aapcs" fn aapcs() {}
diff --git a/tests/ui/abi/unsupported.x64.stderr b/tests/ui/abi/unsupported.x64.stderr
index ea62cb15148..4a2b7e74969 100644
--- a/tests/ui/abi/unsupported.x64.stderr
+++ b/tests/ui/abi/unsupported.x64.stderr
@@ -1,53 +1,47 @@
 error[E0570]: `"ptx-kernel"` is not a supported ABI for the current target
-  --> $DIR/unsupported.rs:30:1
+  --> $DIR/unsupported.rs:29:1
    |
 LL | extern "ptx-kernel" fn ptx() {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error[E0570]: `"amdgpu-kernel"` is not a supported ABI for the current target
-  --> $DIR/unsupported.rs:32:1
-   |
-LL | extern "amdgpu-kernel" fn amdgpu() {}
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
 error[E0570]: `"wasm"` is not a supported ABI for the current target
-  --> $DIR/unsupported.rs:34:1
+  --> $DIR/unsupported.rs:31:1
    |
 LL | extern "wasm" fn wasm() {}
    | ^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0570]: `"aapcs"` is not a supported ABI for the current target
-  --> $DIR/unsupported.rs:36:1
+  --> $DIR/unsupported.rs:33:1
    |
 LL | extern "aapcs" fn aapcs() {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0570]: `"msp430-interrupt"` is not a supported ABI for the current target
-  --> $DIR/unsupported.rs:42:1
+  --> $DIR/unsupported.rs:39:1
    |
 LL | extern "msp430-interrupt" fn msp430() {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0570]: `"avr-interrupt"` is not a supported ABI for the current target
-  --> $DIR/unsupported.rs:44:1
+  --> $DIR/unsupported.rs:41:1
    |
 LL | extern "avr-interrupt" fn avr() {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0570]: `"riscv-interrupt-m"` is not a supported ABI for the current target
-  --> $DIR/unsupported.rs:46:1
+  --> $DIR/unsupported.rs:43:1
    |
 LL | extern "riscv-interrupt-m" fn riscv() {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error[E0570]: `"thiscall"` is not a supported ABI for the current target
-  --> $DIR/unsupported.rs:56:1
+  --> $DIR/unsupported.rs:53:1
    |
 LL | extern "thiscall" fn thiscall() {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: use of calling convention not supported on this target
-  --> $DIR/unsupported.rs:62:1
+  --> $DIR/unsupported.rs:59:1
    |
 LL | extern "stdcall" fn stdcall() {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -56,6 +50,6 @@ LL | extern "stdcall" fn stdcall() {}
    = note: for more information, see issue #87678 <https://github.com/rust-lang/rust/issues/87678>
    = note: `#[warn(unsupported_calling_conventions)]` on by default
 
-error: aborting due to 8 previous errors; 1 warning emitted
+error: aborting due to 7 previous errors; 1 warning emitted
 
 For more information about this error, try `rustc --explain E0570`.
diff --git a/tests/ui/associated-consts/issue-58022.stderr b/tests/ui/associated-consts/issue-58022.stderr
index 82cbc9ed3b0..6ce995eaab7 100644
--- a/tests/ui/associated-consts/issue-58022.stderr
+++ b/tests/ui/associated-consts/issue-58022.stderr
@@ -13,7 +13,7 @@ error[E0277]: the size for values of type `[u8]` cannot be known at compilation
 LL |     fn new(slice: &[u8; Self::SIZE]) -> Self {
    |                                         ^^^^ doesn't have a size known at compile-time
    |
-   = help: within `Bar<[u8]>`, the trait `Sized` is not implemented for `[u8]`
+   = help: within `Bar<[u8]>`, the trait `Sized` is not implemented for `[u8]`, which is required by `Bar<[u8]>: Sized`
 note: required because it appears within the type `Bar<[u8]>`
   --> $DIR/issue-58022.rs:8:12
    |
diff --git a/tests/ui/associated-type-bounds/return-type-notation/basic.without.stderr b/tests/ui/associated-type-bounds/return-type-notation/basic.without.stderr
index f576cc9c95f..dde7036231e 100644
--- a/tests/ui/associated-type-bounds/return-type-notation/basic.without.stderr
+++ b/tests/ui/associated-type-bounds/return-type-notation/basic.without.stderr
@@ -13,7 +13,7 @@ error: future cannot be sent between threads safely
 LL |     is_send(foo::<T>());
    |             ^^^^^^^^^^ future returned by `foo` is not `Send`
    |
-   = help: within `impl Future<Output = Result<(), ()>>`, the trait `Send` is not implemented for `impl Future<Output = Result<(), ()>> { <T as Foo>::method() }`
+   = help: within `impl Future<Output = Result<(), ()>>`, the trait `Send` is not implemented for `impl Future<Output = Result<(), ()>> { <T as Foo>::method() }`, which is required by `impl Future<Output = Result<(), ()>>: Send`
 note: future is not `Send` as it awaits another future which is not `Send`
   --> $DIR/basic.rs:13:5
    |
diff --git a/tests/ui/associated-types/defaults-suitability.stderr b/tests/ui/associated-types/defaults-suitability.stderr
index 0a8ad0f89e2..82b35a48637 100644
--- a/tests/ui/associated-types/defaults-suitability.stderr
+++ b/tests/ui/associated-types/defaults-suitability.stderr
@@ -39,7 +39,7 @@ error[E0277]: the trait bound `T: Clone` is not satisfied
   --> $DIR/defaults-suitability.rs:28:23
    |
 LL |     type Bar: Clone = Vec<T>;
-   |                       ^^^^^^ the trait `Clone` is not implemented for `T`
+   |                       ^^^^^^ the trait `Clone` is not implemented for `T`, which is required by `Vec<T>: Clone`
    |
    = note: required for `Vec<T>` to implement `Clone`
 note: required by a bound in `Foo::Bar`
@@ -88,7 +88,7 @@ error[E0277]: the trait bound `<Self as Foo2<T>>::Baz: Clone` is not satisfied
   --> $DIR/defaults-suitability.rs:65:23
    |
 LL |     type Bar: Clone = Vec<Self::Baz>;
-   |                       ^^^^^^^^^^^^^^ the trait `Clone` is not implemented for `<Self as Foo2<T>>::Baz`
+   |                       ^^^^^^^^^^^^^^ the trait `Clone` is not implemented for `<Self as Foo2<T>>::Baz`, which is required by `Vec<<Self as Foo2<T>>::Baz>: Clone`
    |
    = note: required for `Vec<<Self as Foo2<T>>::Baz>` to implement `Clone`
 note: required by a bound in `Foo2::Bar`
@@ -105,7 +105,7 @@ error[E0277]: the trait bound `<Self as Foo25<T>>::Baz: Clone` is not satisfied
   --> $DIR/defaults-suitability.rs:74:23
    |
 LL |     type Bar: Clone = Vec<Self::Baz>;
-   |                       ^^^^^^^^^^^^^^ the trait `Clone` is not implemented for `<Self as Foo25<T>>::Baz`
+   |                       ^^^^^^^^^^^^^^ the trait `Clone` is not implemented for `<Self as Foo25<T>>::Baz`, which is required by `Vec<<Self as Foo25<T>>::Baz>: Clone`
    |
    = note: required for `Vec<<Self as Foo25<T>>::Baz>` to implement `Clone`
 note: required by a bound in `Foo25::Bar`
diff --git a/tests/ui/associated-types/hr-associated-type-bound-1.stderr b/tests/ui/associated-types/hr-associated-type-bound-1.stderr
index ab5dc803cdf..01005b6b22d 100644
--- a/tests/ui/associated-types/hr-associated-type-bound-1.stderr
+++ b/tests/ui/associated-types/hr-associated-type-bound-1.stderr
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `str: Clone` is not satisfied
   --> $DIR/hr-associated-type-bound-1.rs:12:14
    |
 LL |     type U = str;
-   |              ^^^ the trait `Clone` is not implemented for `str`
+   |              ^^^ the trait `Clone` is not implemented for `str`, which is required by `for<'b> <i32 as X<'b>>::U: Clone`
    |
    = help: the trait `Clone` is implemented for `String`
 note: required by a bound in `X`
diff --git a/tests/ui/associated-types/hr-associated-type-bound-param-1.stderr b/tests/ui/associated-types/hr-associated-type-bound-param-1.stderr
index 9e039364224..0031d205b84 100644
--- a/tests/ui/associated-types/hr-associated-type-bound-param-1.stderr
+++ b/tests/ui/associated-types/hr-associated-type-bound-param-1.stderr
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `str: Clone` is not satisfied
   --> $DIR/hr-associated-type-bound-param-1.rs:14:14
    |
 LL |     type V = str;
-   |              ^^^ the trait `Clone` is not implemented for `str`
+   |              ^^^ the trait `Clone` is not implemented for `str`, which is required by `for<'b> <u8 as Y<'b, u8>>::V: Clone`
    |
    = help: the trait `Clone` is implemented for `String`
 note: required by a bound in `Y`
diff --git a/tests/ui/associated-types/hr-associated-type-bound-param-2.stderr b/tests/ui/associated-types/hr-associated-type-bound-param-2.stderr
index 1a749007ab6..bb484da6a77 100644
--- a/tests/ui/associated-types/hr-associated-type-bound-param-2.stderr
+++ b/tests/ui/associated-types/hr-associated-type-bound-param-2.stderr
@@ -18,7 +18,7 @@ error[E0277]: the trait bound `str: Clone` is not satisfied
   --> $DIR/hr-associated-type-bound-param-2.rs:15:14
    |
 LL |     type W = str;
-   |              ^^^ the trait `Clone` is not implemented for `str`
+   |              ^^^ the trait `Clone` is not implemented for `str`, which is required by `for<'b> <u16 as Z<'b, u16>>::W: Clone`
    |
    = help: the trait `Clone` is implemented for `String`
 note: required by a bound in `Z`
diff --git a/tests/ui/associated-types/hr-associated-type-bound-param-3.stderr b/tests/ui/associated-types/hr-associated-type-bound-param-3.stderr
index f8be4ec2410..f4d2f43a9b4 100644
--- a/tests/ui/associated-types/hr-associated-type-bound-param-3.stderr
+++ b/tests/ui/associated-types/hr-associated-type-bound-param-3.stderr
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `str: Clone` is not satisfied
   --> $DIR/hr-associated-type-bound-param-3.rs:13:14
    |
 LL |     type U = str;
-   |              ^^^ the trait `Clone` is not implemented for `str`
+   |              ^^^ the trait `Clone` is not implemented for `str`, which is required by `for<'b> <(T,) as X<'b, (T,)>>::U: Clone`
    |
    = help: the trait `Clone` is implemented for `String`
 note: required by a bound in `X`
diff --git a/tests/ui/associated-types/hr-associated-type-bound-param-4.stderr b/tests/ui/associated-types/hr-associated-type-bound-param-4.stderr
index 22c4bd68690..7f03d155391 100644
--- a/tests/ui/associated-types/hr-associated-type-bound-param-4.stderr
+++ b/tests/ui/associated-types/hr-associated-type-bound-param-4.stderr
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `str: Clone` is not satisfied
   --> $DIR/hr-associated-type-bound-param-4.rs:13:14
    |
 LL |     type U = str;
-   |              ^^^ the trait `Clone` is not implemented for `str`
+   |              ^^^ the trait `Clone` is not implemented for `str`, which is required by `for<'b> <(T,) as X<'b, T>>::U: Clone`
    |
    = help: the trait `Clone` is implemented for `String`
 note: required by a bound in `X`
diff --git a/tests/ui/associated-types/hr-associated-type-bound-param-5.stderr b/tests/ui/associated-types/hr-associated-type-bound-param-5.stderr
index aae80a9b2e1..fbbc2f45772 100644
--- a/tests/ui/associated-types/hr-associated-type-bound-param-5.stderr
+++ b/tests/ui/associated-types/hr-associated-type-bound-param-5.stderr
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `str: Clone` is not satisfied
   --> $DIR/hr-associated-type-bound-param-5.rs:26:14
    |
 LL |     type U = str;
-   |              ^^^ the trait `Clone` is not implemented for `str`
+   |              ^^^ the trait `Clone` is not implemented for `str`, which is required by `for<'b> <<Vec<T> as Cycle>::Next as X<'b, <Vec<T> as Cycle>::Next>>::U: Clone`
    |
    = help: the trait `Clone` is implemented for `String`
 note: required by a bound in `X`
@@ -18,7 +18,7 @@ error[E0277]: the trait bound `str: Clone` is not satisfied
   --> $DIR/hr-associated-type-bound-param-5.rs:31:14
    |
 LL |     type U = str;
-   |              ^^^ the trait `Clone` is not implemented for `str`
+   |              ^^^ the trait `Clone` is not implemented for `str`, which is required by `for<'b> <<Box<T> as Cycle>::Next as X<'b, <Box<T> as Cycle>::Next>>::U: Clone`
    |
    = help: the trait `Clone` is implemented for `String`
 note: required by a bound in `X`
diff --git a/tests/ui/associated-types/issue-38821.stderr b/tests/ui/associated-types/issue-38821.stderr
index 0e34f541ea3..50d622c89bb 100644
--- a/tests/ui/associated-types/issue-38821.stderr
+++ b/tests/ui/associated-types/issue-38821.stderr
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `<Col as Expression>::SqlType: NotNull` is not sat
   --> $DIR/issue-38821.rs:23:17
    |
 LL | #[derive(Debug, Copy, Clone)]
-   |                 ^^^^ the trait `NotNull` is not implemented for `<Col as Expression>::SqlType`
+   |                 ^^^^ the trait `NotNull` is not implemented for `<Col as Expression>::SqlType`, which is required by `<Col as Expression>::SqlType: IntoNullable`
    |
 note: required for `<Col as Expression>::SqlType` to implement `IntoNullable`
   --> $DIR/issue-38821.rs:9:18
@@ -21,7 +21,7 @@ error[E0277]: the trait bound `<Col as Expression>::SqlType: NotNull` is not sat
   --> $DIR/issue-38821.rs:38:1
    |
 LL | pub enum ColumnInsertValue<Col, Expr> where
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `NotNull` is not implemented for `<Col as Expression>::SqlType`
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `NotNull` is not implemented for `<Col as Expression>::SqlType`, which is required by `<Col as Expression>::SqlType: IntoNullable`
    |
 note: required for `<Col as Expression>::SqlType` to implement `IntoNullable`
   --> $DIR/issue-38821.rs:9:18
@@ -45,7 +45,7 @@ LL | |     Col: Column,
 ...  |
 LL | |     Default(Col),
 LL | | }
-   | |_^ the trait `NotNull` is not implemented for `<Col as Expression>::SqlType`
+   | |_^ the trait `NotNull` is not implemented for `<Col as Expression>::SqlType`, which is required by `<Col as Expression>::SqlType: IntoNullable`
    |
 note: required for `<Col as Expression>::SqlType` to implement `IntoNullable`
   --> $DIR/issue-38821.rs:9:18
@@ -63,7 +63,7 @@ error[E0277]: the trait bound `<Col as Expression>::SqlType: NotNull` is not sat
   --> $DIR/issue-38821.rs:23:10
    |
 LL | #[derive(Debug, Copy, Clone)]
-   |          ^^^^^ the trait `NotNull` is not implemented for `<Col as Expression>::SqlType`
+   |          ^^^^^ the trait `NotNull` is not implemented for `<Col as Expression>::SqlType`, which is required by `<Col as Expression>::SqlType: IntoNullable`
    |
 note: required for `<Col as Expression>::SqlType` to implement `IntoNullable`
   --> $DIR/issue-38821.rs:9:18
@@ -82,7 +82,7 @@ error[E0277]: the trait bound `<Col as Expression>::SqlType: NotNull` is not sat
   --> $DIR/issue-38821.rs:23:10
    |
 LL | #[derive(Debug, Copy, Clone)]
-   |          ^^^^^ the trait `NotNull` is not implemented for `<Col as Expression>::SqlType`
+   |          ^^^^^ the trait `NotNull` is not implemented for `<Col as Expression>::SqlType`, which is required by `<Col as Expression>::SqlType: IntoNullable`
    |
 note: required for `<Col as Expression>::SqlType` to implement `IntoNullable`
   --> $DIR/issue-38821.rs:9:18
@@ -102,7 +102,7 @@ error[E0277]: the trait bound `<Col as Expression>::SqlType: NotNull` is not sat
   --> $DIR/issue-38821.rs:23:10
    |
 LL | #[derive(Debug, Copy, Clone)]
-   |          ^^^^^ the trait `NotNull` is not implemented for `<Col as Expression>::SqlType`
+   |          ^^^^^ the trait `NotNull` is not implemented for `<Col as Expression>::SqlType`, which is required by `<Col as Expression>::SqlType: IntoNullable`
    |
 note: required for `<Col as Expression>::SqlType` to implement `IntoNullable`
   --> $DIR/issue-38821.rs:9:18
@@ -117,7 +117,7 @@ error[E0277]: the trait bound `<Col as Expression>::SqlType: NotNull` is not sat
   --> $DIR/issue-38821.rs:23:10
    |
 LL | #[derive(Debug, Copy, Clone)]
-   |          ^^^^^ the trait `NotNull` is not implemented for `<Col as Expression>::SqlType`
+   |          ^^^^^ the trait `NotNull` is not implemented for `<Col as Expression>::SqlType`, which is required by `<Col as Expression>::SqlType: IntoNullable`
    |
 note: required for `<Col as Expression>::SqlType` to implement `IntoNullable`
   --> $DIR/issue-38821.rs:9:18
@@ -133,7 +133,7 @@ error[E0277]: the trait bound `<Col as Expression>::SqlType: NotNull` is not sat
   --> $DIR/issue-38821.rs:23:17
    |
 LL | #[derive(Debug, Copy, Clone)]
-   |                 ^^^^ the trait `NotNull` is not implemented for `<Col as Expression>::SqlType`
+   |                 ^^^^ the trait `NotNull` is not implemented for `<Col as Expression>::SqlType`, which is required by `<Col as Expression>::SqlType: IntoNullable`
    |
 note: required for `<Col as Expression>::SqlType` to implement `IntoNullable`
   --> $DIR/issue-38821.rs:9:18
@@ -153,7 +153,7 @@ error[E0277]: the trait bound `<Col as Expression>::SqlType: NotNull` is not sat
   --> $DIR/issue-38821.rs:23:23
    |
 LL | #[derive(Debug, Copy, Clone)]
-   |                       ^^^^^ the trait `NotNull` is not implemented for `<Col as Expression>::SqlType`
+   |                       ^^^^^ the trait `NotNull` is not implemented for `<Col as Expression>::SqlType`, which is required by `<Col as Expression>::SqlType: IntoNullable`
    |
 note: required for `<Col as Expression>::SqlType` to implement `IntoNullable`
   --> $DIR/issue-38821.rs:9:18
@@ -172,7 +172,7 @@ error[E0277]: the trait bound `<Col as Expression>::SqlType: NotNull` is not sat
   --> $DIR/issue-38821.rs:23:23
    |
 LL | #[derive(Debug, Copy, Clone)]
-   |                       ^^^^^ the trait `NotNull` is not implemented for `<Col as Expression>::SqlType`
+   |                       ^^^^^ the trait `NotNull` is not implemented for `<Col as Expression>::SqlType`, which is required by `<Col as Expression>::SqlType: IntoNullable`
    |
 note: required for `<Col as Expression>::SqlType` to implement `IntoNullable`
   --> $DIR/issue-38821.rs:9:18
@@ -192,7 +192,7 @@ error[E0277]: the trait bound `<Col as Expression>::SqlType: NotNull` is not sat
   --> $DIR/issue-38821.rs:23:23
    |
 LL | #[derive(Debug, Copy, Clone)]
-   |                       ^^^^^ the trait `NotNull` is not implemented for `<Col as Expression>::SqlType`
+   |                       ^^^^^ the trait `NotNull` is not implemented for `<Col as Expression>::SqlType`, which is required by `<Col as Expression>::SqlType: IntoNullable`
    |
 note: required for `<Col as Expression>::SqlType` to implement `IntoNullable`
   --> $DIR/issue-38821.rs:9:18
@@ -207,7 +207,7 @@ error[E0277]: the trait bound `<Col as Expression>::SqlType: NotNull` is not sat
   --> $DIR/issue-38821.rs:23:23
    |
 LL | #[derive(Debug, Copy, Clone)]
-   |                       ^^^^^ the trait `NotNull` is not implemented for `<Col as Expression>::SqlType`
+   |                       ^^^^^ the trait `NotNull` is not implemented for `<Col as Expression>::SqlType`, which is required by `<Col as Expression>::SqlType: IntoNullable`
    |
 note: required for `<Col as Expression>::SqlType` to implement `IntoNullable`
   --> $DIR/issue-38821.rs:9:18
@@ -223,7 +223,7 @@ error[E0277]: the trait bound `<Col as Expression>::SqlType: NotNull` is not sat
   --> $DIR/issue-38821.rs:23:10
    |
 LL | #[derive(Debug, Copy, Clone)]
-   |          ^^^^^ the trait `NotNull` is not implemented for `<Col as Expression>::SqlType`
+   |          ^^^^^ the trait `NotNull` is not implemented for `<Col as Expression>::SqlType`, which is required by `<Col as Expression>::SqlType: IntoNullable`
    |
 note: required for `<Col as Expression>::SqlType` to implement `IntoNullable`
   --> $DIR/issue-38821.rs:9:18
@@ -239,7 +239,7 @@ error[E0277]: the trait bound `<Col as Expression>::SqlType: NotNull` is not sat
   --> $DIR/issue-38821.rs:23:10
    |
 LL | #[derive(Debug, Copy, Clone)]
-   |          ^^^^^ the trait `NotNull` is not implemented for `<Col as Expression>::SqlType`
+   |          ^^^^^ the trait `NotNull` is not implemented for `<Col as Expression>::SqlType`, which is required by `<Col as Expression>::SqlType: IntoNullable`
    |
 note: required for `<Col as Expression>::SqlType` to implement `IntoNullable`
   --> $DIR/issue-38821.rs:9:18
@@ -255,7 +255,7 @@ error[E0277]: the trait bound `<Col as Expression>::SqlType: NotNull` is not sat
   --> $DIR/issue-38821.rs:23:23
    |
 LL | #[derive(Debug, Copy, Clone)]
-   |                       ^^^^^ the trait `NotNull` is not implemented for `<Col as Expression>::SqlType`
+   |                       ^^^^^ the trait `NotNull` is not implemented for `<Col as Expression>::SqlType`, which is required by `<Col as Expression>::SqlType: IntoNullable`
    |
 note: required for `<Col as Expression>::SqlType` to implement `IntoNullable`
   --> $DIR/issue-38821.rs:9:18
@@ -271,7 +271,7 @@ error[E0277]: the trait bound `<Col as Expression>::SqlType: NotNull` is not sat
   --> $DIR/issue-38821.rs:23:23
    |
 LL | #[derive(Debug, Copy, Clone)]
-   |                       ^^^^^ the trait `NotNull` is not implemented for `<Col as Expression>::SqlType`
+   |                       ^^^^^ the trait `NotNull` is not implemented for `<Col as Expression>::SqlType`, which is required by `<Col as Expression>::SqlType: IntoNullable`
    |
 note: required for `<Col as Expression>::SqlType` to implement `IntoNullable`
   --> $DIR/issue-38821.rs:9:18
diff --git a/tests/ui/associated-types/issue-43784-associated-type.stderr b/tests/ui/associated-types/issue-43784-associated-type.stderr
index 529fc1f119a..b2cbe8ee86e 100644
--- a/tests/ui/associated-types/issue-43784-associated-type.stderr
+++ b/tests/ui/associated-types/issue-43784-associated-type.stderr
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `T: Copy` is not satisfied
   --> $DIR/issue-43784-associated-type.rs:14:18
    |
 LL |     type Assoc = T;
-   |                  ^ the trait `Copy` is not implemented for `T`
+   |                  ^ the trait `Copy` is not implemented for `T`, which is required by `<T as Complete>::Assoc: Partial<T>`
    |
 note: required for `<T as Complete>::Assoc` to implement `Partial<T>`
   --> $DIR/issue-43784-associated-type.rs:1:11
diff --git a/tests/ui/associated-types/issue-65774-1.stderr b/tests/ui/associated-types/issue-65774-1.stderr
index 9c77a25c432..9748a8fbbf4 100644
--- a/tests/ui/associated-types/issue-65774-1.stderr
+++ b/tests/ui/associated-types/issue-65774-1.stderr
@@ -15,7 +15,7 @@ error[E0277]: the trait bound `T: MyDisplay` is not satisfied
   --> $DIR/issue-65774-1.rs:44:76
    |
 LL |         let closure = |config: &mut <S as MPU>::MpuConfig| writer.my_write(&config);
-   |                                                                            ^^^^^^^ the trait `MyDisplay` is not implemented for `T`
+   |                                                                            ^^^^^^^ the trait `MyDisplay` is not implemented for `T`, which is required by `&mut T: MyDisplay`
    |
    = help: the trait `MyDisplay` is implemented for `&'a mut T`
 note: required for `&mut T` to implement `MyDisplay`
diff --git a/tests/ui/associated-types/substs-ppaux.normal.stderr b/tests/ui/associated-types/substs-ppaux.normal.stderr
index 015b22f790f..93118616f02 100644
--- a/tests/ui/associated-types/substs-ppaux.normal.stderr
+++ b/tests/ui/associated-types/substs-ppaux.normal.stderr
@@ -76,7 +76,7 @@ error[E0277]: the size for values of type `str` cannot be known at compilation t
 LL |     <str as Foo<u8>>::bar;
    |      ^^^ doesn't have a size known at compile-time
    |
-   = help: the trait `Sized` is not implemented for `str`
+   = help: the trait `Sized` is not implemented for `str`, which is required by `str: Foo<'_, '_, u8>`
 note: required for `str` to implement `Foo<'_, '_, u8>`
   --> $DIR/substs-ppaux.rs:11:17
    |
diff --git a/tests/ui/associated-types/substs-ppaux.verbose.stderr b/tests/ui/associated-types/substs-ppaux.verbose.stderr
index 484581b1028..13d3156fb80 100644
--- a/tests/ui/associated-types/substs-ppaux.verbose.stderr
+++ b/tests/ui/associated-types/substs-ppaux.verbose.stderr
@@ -76,7 +76,7 @@ error[E0277]: the size for values of type `str` cannot be known at compilation t
 LL |     <str as Foo<u8>>::bar;
    |      ^^^ doesn't have a size known at compile-time
    |
-   = help: the trait `Sized` is not implemented for `str`
+   = help: the trait `Sized` is not implemented for `str`, which is required by `str: Foo<'?0, '?1, u8>`
 note: required for `str` to implement `Foo<'?0, '?1, u8>`
   --> $DIR/substs-ppaux.rs:11:17
    |
diff --git a/tests/ui/async-await/async-await-let-else.stderr b/tests/ui/async-await/async-await-let-else.stderr
index b360aab6b59..057906b49a3 100644
--- a/tests/ui/async-await/async-await-let-else.stderr
+++ b/tests/ui/async-await/async-await-let-else.stderr
@@ -4,7 +4,7 @@ error: future cannot be sent between threads safely
 LL |     is_send(foo(Some(true)));
    |             ^^^^^^^^^^^^^^^ future returned by `foo` is not `Send`
    |
-   = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `Rc<()>`
+   = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `Rc<()>`, which is required by `impl Future<Output = ()>: Send`
 note: future is not `Send` as this value is used across an await
   --> $DIR/async-await-let-else.rs:8:15
    |
@@ -29,7 +29,7 @@ LL |     is_send(foo2(Some(true)));
    |     |
    |     required by a bound introduced by this call
    |
-   = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `Rc<()>`
+   = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `Rc<()>`, which is required by `impl Future<Output = ()>: Send`
 note: required because it's used within this `async` fn body
   --> $DIR/async-await-let-else.rs:24:29
    |
@@ -61,7 +61,7 @@ error: future cannot be sent between threads safely
 LL |     is_send(foo3(Some(true)));
    |             ^^^^^^^^^^^^^^^^ future returned by `foo3` is not `Send`
    |
-   = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `Rc<()>`
+   = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `Rc<()>`, which is required by `impl Future<Output = ()>: Send`
 note: future is not `Send` as this value is used across an await
   --> $DIR/async-await-let-else.rs:30:29
    |
@@ -81,7 +81,7 @@ error: future cannot be sent between threads safely
 LL |     is_send(foo4(Some(true)));
    |             ^^^^^^^^^^^^^^^^ future returned by `foo4` is not `Send`
    |
-   = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `Rc<()>`
+   = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `Rc<()>`, which is required by `impl Future<Output = ()>: Send`
 note: future is not `Send` as this value is used across an await
   --> $DIR/async-await-let-else.rs:38:15
    |
diff --git a/tests/ui/async-await/async-fn-nonsend.stderr b/tests/ui/async-await/async-fn-nonsend.stderr
index 0ced6c36f47..8b245281da9 100644
--- a/tests/ui/async-await/async-fn-nonsend.stderr
+++ b/tests/ui/async-await/async-fn-nonsend.stderr
@@ -4,7 +4,7 @@ error: future cannot be sent between threads safely
 LL |     assert_send(non_send_temporary_in_match());
    |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ future returned by `non_send_temporary_in_match` is not `Send`
    |
-   = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `Rc<()>`
+   = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `Rc<()>`, which is required by `impl Future<Output = ()>: Send`
 note: future is not `Send` as this value is used across an await
   --> $DIR/async-fn-nonsend.rs:33:26
    |
@@ -24,7 +24,7 @@ error: future cannot be sent between threads safely
 LL |     assert_send(non_sync_with_method_call());
    |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ future returned by `non_sync_with_method_call` is not `Send`
    |
-   = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `dyn std::fmt::Write`
+   = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `dyn std::fmt::Write`, which is required by `impl Future<Output = ()>: Send`
 note: future is not `Send` as this value is used across an await
   --> $DIR/async-fn-nonsend.rs:46:15
    |
diff --git a/tests/ui/async-await/async-is-unwindsafe.stderr b/tests/ui/async-await/async-is-unwindsafe.stderr
index 4098b29c557..5d87fc74768 100644
--- a/tests/ui/async-await/async-is-unwindsafe.stderr
+++ b/tests/ui/async-await/async-is-unwindsafe.stderr
@@ -15,7 +15,7 @@ LL | ||     });
    |  |_____|
    |        within this `{async block@$DIR/async-is-unwindsafe.rs:12:19: 29:6}`
    |
-   = help: within `{async block@$DIR/async-is-unwindsafe.rs:12:19: 29:6}`, the trait `UnwindSafe` is not implemented for `&mut Context<'_>`
+   = help: within `{async block@$DIR/async-is-unwindsafe.rs:12:19: 29:6}`, the trait `UnwindSafe` is not implemented for `&mut Context<'_>`, which is required by `{async block@$DIR/async-is-unwindsafe.rs:12:19: 29:6}: UnwindSafe`
    = note: `UnwindSafe` is implemented for `&Context<'_>`, but not for `&mut Context<'_>`
 note: future does not implement `UnwindSafe` as this value is used across an await
   --> $DIR/async-is-unwindsafe.rs:25:18
diff --git a/tests/ui/async-await/debug-ice-attempted-to-add-with-overflow.stderr b/tests/ui/async-await/debug-ice-attempted-to-add-with-overflow.stderr
index 8c9d06c79ca..eab5bea681c 100644
--- a/tests/ui/async-await/debug-ice-attempted-to-add-with-overflow.stderr
+++ b/tests/ui/async-await/debug-ice-attempted-to-add-with-overflow.stderr
@@ -7,7 +7,7 @@ LL |     [0usize; 0xffff_ffff_ffff_ffff].await;
    |                                    |`[usize; usize::MAX]` is not a future
    |                                    help: remove the `.await`
    |
-   = help: the trait `Future` is not implemented for `[usize; usize::MAX]`
+   = help: the trait `Future` is not implemented for `[usize; usize::MAX]`, which is required by `[usize; usize::MAX]: IntoFuture`
    = note: [usize; usize::MAX] must be a future or must implement `IntoFuture` to be awaited
    = note: required for `[usize; usize::MAX]` to implement `IntoFuture`
 
diff --git a/tests/ui/async-await/drop-track-bad-field-in-fru.stderr b/tests/ui/async-await/drop-track-bad-field-in-fru.stderr
index 721e0106293..53cdc9b61d3 100644
--- a/tests/ui/async-await/drop-track-bad-field-in-fru.stderr
+++ b/tests/ui/async-await/drop-track-bad-field-in-fru.stderr
@@ -15,7 +15,7 @@ LL |     None { value: (), ..Default::default() }.await;
    |                                             |`Option<_>` is not a future
    |                                             help: remove the `.await`
    |
-   = help: the trait `Future` is not implemented for `Option<_>`
+   = help: the trait `Future` is not implemented for `Option<_>`, which is required by `Option<_>: IntoFuture`
    = note: Option<_> must be a future or must implement `IntoFuture` to be awaited
    = note: required for `Option<_>` to implement `IntoFuture`
 
diff --git a/tests/ui/async-await/drop-track-field-assign-nonsend.stderr b/tests/ui/async-await/drop-track-field-assign-nonsend.stderr
index 9fce4d61b3b..ce2cee6ed47 100644
--- a/tests/ui/async-await/drop-track-field-assign-nonsend.stderr
+++ b/tests/ui/async-await/drop-track-field-assign-nonsend.stderr
@@ -4,7 +4,7 @@ error: future cannot be sent between threads safely
 LL |     assert_send(agent.handle());
    |                 ^^^^^^^^^^^^^^ future returned by `handle` is not `Send`
    |
-   = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `Rc<String>`
+   = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `Rc<String>`, which is required by `impl Future<Output = ()>: Send`
 note: future is not `Send` as this value is used across an await
   --> $DIR/drop-track-field-assign-nonsend.rs:20:39
    |
diff --git a/tests/ui/async-await/field-assign-nonsend.stderr b/tests/ui/async-await/field-assign-nonsend.stderr
index 418a0829c65..525a2cc78b4 100644
--- a/tests/ui/async-await/field-assign-nonsend.stderr
+++ b/tests/ui/async-await/field-assign-nonsend.stderr
@@ -4,7 +4,7 @@ error: future cannot be sent between threads safely
 LL |     assert_send(agent.handle());
    |                 ^^^^^^^^^^^^^^ future returned by `handle` is not `Send`
    |
-   = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `Rc<String>`
+   = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `Rc<String>`, which is required by `impl Future<Output = ()>: Send`
 note: future is not `Send` as this value is used across an await
   --> $DIR/field-assign-nonsend.rs:20:39
    |
diff --git a/tests/ui/async-await/in-trait/missing-send-bound.stderr b/tests/ui/async-await/in-trait/missing-send-bound.stderr
index aeabb5931df..93f37a9a8e9 100644
--- a/tests/ui/async-await/in-trait/missing-send-bound.stderr
+++ b/tests/ui/async-await/in-trait/missing-send-bound.stderr
@@ -4,7 +4,7 @@ error: future cannot be sent between threads safely
 LL |     assert_is_send(test::<T>());
    |                    ^^^^^^^^^^^ future returned by `test` is not `Send`
    |
-   = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `impl Future<Output = ()>`
+   = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `impl Future<Output = ()>`, which is required by `impl Future<Output = ()>: Send`
 note: future is not `Send` as it awaits another future which is not `Send`
   --> $DIR/missing-send-bound.rs:9:5
    |
diff --git a/tests/ui/async-await/issue-101715.stderr b/tests/ui/async-await/issue-101715.stderr
index f6af15c00d6..3b429793b78 100644
--- a/tests/ui/async-await/issue-101715.stderr
+++ b/tests/ui/async-await/issue-101715.stderr
@@ -7,7 +7,7 @@ LL |         .await
    |         |`()` is not a future
    |         help: remove the `.await`
    |
-   = help: the trait `Future` is not implemented for `()`
+   = help: the trait `Future` is not implemented for `()`, which is required by `(): IntoFuture`
    = note: () must be a future or must implement `IntoFuture` to be awaited
    = note: required for `()` to implement `IntoFuture`
 
diff --git a/tests/ui/async-await/issue-64130-1-sync.stderr b/tests/ui/async-await/issue-64130-1-sync.stderr
index 5428d7ef71b..15f49124f6f 100644
--- a/tests/ui/async-await/issue-64130-1-sync.stderr
+++ b/tests/ui/async-await/issue-64130-1-sync.stderr
@@ -4,7 +4,7 @@ error: future cannot be shared between threads safely
 LL |     is_sync(bar());
    |             ^^^^^ future returned by `bar` is not `Sync`
    |
-   = help: within `impl Future<Output = ()>`, the trait `Sync` is not implemented for `Foo`
+   = help: within `impl Future<Output = ()>`, the trait `Sync` is not implemented for `Foo`, which is required by `impl Future<Output = ()>: Sync`
 note: future is not `Sync` as this value is used across an await
   --> $DIR/issue-64130-1-sync.rs:15:11
    |
diff --git a/tests/ui/async-await/issue-64130-2-send.stderr b/tests/ui/async-await/issue-64130-2-send.stderr
index f05e954d2d7..67368314b1b 100644
--- a/tests/ui/async-await/issue-64130-2-send.stderr
+++ b/tests/ui/async-await/issue-64130-2-send.stderr
@@ -4,7 +4,7 @@ error: future cannot be sent between threads safely
 LL |     is_send(bar());
    |             ^^^^^ future returned by `bar` is not `Send`
    |
-   = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `Foo`
+   = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `Foo`, which is required by `impl Future<Output = ()>: Send`
 note: future is not `Send` as this value is used across an await
   --> $DIR/issue-64130-2-send.rs:15:11
    |
diff --git a/tests/ui/async-await/issue-64130-3-other.stderr b/tests/ui/async-await/issue-64130-3-other.stderr
index 3ac30bdc23e..e3a73920c92 100644
--- a/tests/ui/async-await/issue-64130-3-other.stderr
+++ b/tests/ui/async-await/issue-64130-3-other.stderr
@@ -5,7 +5,7 @@ LL | async fn bar() {
    | -------------- within this `impl Future<Output = ()>`
 ...
 LL |     is_qux(bar());
-   |            ^^^^^ within `impl Future<Output = ()>`, the trait `Qux` is not implemented for `Foo`
+   |            ^^^^^ within `impl Future<Output = ()>`, the trait `Qux` is not implemented for `Foo`, which is required by `impl Future<Output = ()>: Qux`
    |
 note: future does not implement `Qux` as this value is used across an await
   --> $DIR/issue-64130-3-other.rs:18:11
diff --git a/tests/ui/async-await/issue-64130-non-send-future-diags.stderr b/tests/ui/async-await/issue-64130-non-send-future-diags.stderr
index d28807e223b..bd890c83817 100644
--- a/tests/ui/async-await/issue-64130-non-send-future-diags.stderr
+++ b/tests/ui/async-await/issue-64130-non-send-future-diags.stderr
@@ -4,7 +4,7 @@ error: future cannot be sent between threads safely
 LL |     is_send(foo());
    |             ^^^^^ future returned by `foo` is not `Send`
    |
-   = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `MutexGuard<'_, u32>`
+   = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `MutexGuard<'_, u32>`, which is required by `impl Future<Output = ()>: Send`
 note: future is not `Send` as this value is used across an await
   --> $DIR/issue-64130-non-send-future-diags.rs:17:11
    |
diff --git a/tests/ui/async-await/issue-67252-unnamed-future.stderr b/tests/ui/async-await/issue-67252-unnamed-future.stderr
index 62ffb7d2eda..51c06b9c8af 100644
--- a/tests/ui/async-await/issue-67252-unnamed-future.stderr
+++ b/tests/ui/async-await/issue-67252-unnamed-future.stderr
@@ -8,7 +8,7 @@ LL | |         let _a = a;
 LL | |     });
    | |______^ future created by async block is not `Send`
    |
-   = help: within `{async block@$DIR/issue-67252-unnamed-future.rs:18:11: 22:6}`, the trait `Send` is not implemented for `*mut ()`
+   = help: within `{async block@$DIR/issue-67252-unnamed-future.rs:18:11: 22:6}`, the trait `Send` is not implemented for `*mut ()`, which is required by `{async block@$DIR/issue-67252-unnamed-future.rs:18:11: 22:6}: Send`
 note: future is not `Send` as this value is used across an await
   --> $DIR/issue-67252-unnamed-future.rs:20:17
    |
diff --git a/tests/ui/async-await/issue-68112.stderr b/tests/ui/async-await/issue-68112.stderr
index 438782e0e45..f92ac5dd0bc 100644
--- a/tests/ui/async-await/issue-68112.stderr
+++ b/tests/ui/async-await/issue-68112.stderr
@@ -4,7 +4,7 @@ error: future cannot be sent between threads safely
 LL |     require_send(send_fut);
    |     ^^^^^^^^^^^^^^^^^^^^^^ future created by async block is not `Send`
    |
-   = help: the trait `Sync` is not implemented for `RefCell<i32>`
+   = help: the trait `Sync` is not implemented for `RefCell<i32>`, which is required by `{async block@$DIR/issue-68112.rs:29:20: 33:6}: Send`
    = note: if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock` instead
 note: future is not `Send` as it awaits another future which is not `Send`
   --> $DIR/issue-68112.rs:31:17
@@ -23,7 +23,7 @@ error: future cannot be sent between threads safely
 LL |     require_send(send_fut);
    |     ^^^^^^^^^^^^^^^^^^^^^^ future created by async block is not `Send`
    |
-   = help: the trait `Sync` is not implemented for `RefCell<i32>`
+   = help: the trait `Sync` is not implemented for `RefCell<i32>`, which is required by `{async block@$DIR/issue-68112.rs:39:20: 42:6}: Send`
    = note: if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock` instead
 note: future is not `Send` as it awaits another future which is not `Send`
   --> $DIR/issue-68112.rs:40:17
@@ -42,7 +42,7 @@ error[E0277]: `RefCell<i32>` cannot be shared between threads safely
 LL |     require_send(send_fut);
    |     ^^^^^^^^^^^^^^^^^^^^^^ `RefCell<i32>` cannot be shared between threads safely
    |
-   = help: the trait `Sync` is not implemented for `RefCell<i32>`
+   = help: the trait `Sync` is not implemented for `RefCell<i32>`, which is required by `{async block@$DIR/issue-68112.rs:57:20: 61:6}: Send`
    = note: if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock` instead
    = note: required for `Arc<RefCell<i32>>` to implement `Send`
 note: required because it's used within this `async` fn body
diff --git a/tests/ui/async-await/issue-70935-complex-spans.stderr b/tests/ui/async-await/issue-70935-complex-spans.stderr
index 14ef1cbb67c..36e297ed884 100644
--- a/tests/ui/async-await/issue-70935-complex-spans.stderr
+++ b/tests/ui/async-await/issue-70935-complex-spans.stderr
@@ -4,7 +4,7 @@ error[E0277]: `*mut ()` cannot be shared between threads safely
 LL | fn foo(x: NotSync) -> impl Future + Send {
    |                       ^^^^^^^^^^^^^^^^^^ `*mut ()` cannot be shared between threads safely
    |
-   = help: within `NotSync`, the trait `Sync` is not implemented for `*mut ()`
+   = help: within `NotSync`, the trait `Sync` is not implemented for `*mut ()`, which is required by `{async block@$DIR/issue-70935-complex-spans.rs:17:5: 21:6}: Send`
 note: required because it appears within the type `PhantomData<*mut ()>`
   --> $SRC_DIR/core/src/marker.rs:LL:COL
 note: required because it appears within the type `NotSync`
diff --git a/tests/ui/async-await/issue-71137.stderr b/tests/ui/async-await/issue-71137.stderr
index 8739c22a310..75d72e425f5 100644
--- a/tests/ui/async-await/issue-71137.stderr
+++ b/tests/ui/async-await/issue-71137.stderr
@@ -4,7 +4,7 @@ error: future cannot be sent between threads safely
 LL |   fake_spawn(wrong_mutex());
    |              ^^^^^^^^^^^^^ future returned by `wrong_mutex` is not `Send`
    |
-   = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `MutexGuard<'_, i32>`
+   = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `MutexGuard<'_, i32>`, which is required by `impl Future<Output = ()>: Send`
 note: future is not `Send` as this value is used across an await
   --> $DIR/issue-71137.rs:14:26
    |
diff --git a/tests/ui/async-await/issue-72590-type-error-sized.stderr b/tests/ui/async-await/issue-72590-type-error-sized.stderr
index 778423578e1..1b822234d80 100644
--- a/tests/ui/async-await/issue-72590-type-error-sized.stderr
+++ b/tests/ui/async-await/issue-72590-type-error-sized.stderr
@@ -16,7 +16,7 @@ error[E0277]: the size for values of type `str` cannot be known at compilation t
 LL |     async fn frob(self) {}
    |                   ^^^^ doesn't have a size known at compile-time
    |
-   = help: within `Foo`, the trait `Sized` is not implemented for `str`
+   = help: within `Foo`, the trait `Sized` is not implemented for `str`, which is required by `Foo: Sized`
 note: required because it appears within the type `Foo`
   --> $DIR/issue-72590-type-error-sized.rs:5:8
    |
diff --git a/tests/ui/async-await/issues/issue-67893.stderr b/tests/ui/async-await/issues/issue-67893.stderr
index 90c1e976dce..12bbfc12552 100644
--- a/tests/ui/async-await/issues/issue-67893.stderr
+++ b/tests/ui/async-await/issues/issue-67893.stderr
@@ -11,7 +11,7 @@ LL |     g(issue_67893::run())
 LL | pub async fn run() {
    | ------------------ within this `impl Future<Output = ()>`
    |
-   = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `MutexGuard<'_, ()>`
+   = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `MutexGuard<'_, ()>`, which is required by `impl Future<Output = ()>: Send`
    = note: required because it captures the following types: `Arc<Mutex<()>>`, `MutexGuard<'_, ()>`, `impl Future<Output = ()>`
 note: required because it's used within this `async` fn body
   --> $DIR/auxiliary/issue_67893.rs:9:20
diff --git a/tests/ui/async-await/partial-drop-partial-reinit.stderr b/tests/ui/async-await/partial-drop-partial-reinit.stderr
index f088b118730..a6140c6db82 100644
--- a/tests/ui/async-await/partial-drop-partial-reinit.stderr
+++ b/tests/ui/async-await/partial-drop-partial-reinit.stderr
@@ -9,7 +9,7 @@ LL |     gimme_send(foo());
 LL | async fn foo() {
    | -------------- within this `impl Future<Output = ()>`
    |
-   = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `NotSend`
+   = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `NotSend`, which is required by `impl Future<Output = ()>: Send`
    = note: required because it appears within the type `(NotSend,)`
    = note: required because it captures the following types: `(NotSend,)`, `impl Future<Output = ()>`
 note: required because it's used within this `async` fn body
diff --git a/tests/ui/async-await/pin-needed-to-poll-2.stderr b/tests/ui/async-await/pin-needed-to-poll-2.stderr
index 8eb671531e7..e22baabc25b 100644
--- a/tests/ui/async-await/pin-needed-to-poll-2.stderr
+++ b/tests/ui/async-await/pin-needed-to-poll-2.stderr
@@ -2,7 +2,7 @@ error[E0277]: `PhantomPinned` cannot be unpinned
   --> $DIR/pin-needed-to-poll-2.rs:43:18
    |
 LL |         Pin::new(&mut self.sleep).poll(cx)
-   |         -------- ^^^^^^^^^^^^^^^ within `Sleep`, the trait `Unpin` is not implemented for `PhantomPinned`
+   |         -------- ^^^^^^^^^^^^^^^ within `Sleep`, the trait `Unpin` is not implemented for `PhantomPinned`, which is required by `Sleep: Unpin`
    |         |
    |         required by a bound introduced by this call
    |
diff --git a/tests/ui/async-await/unnecessary-await.stderr b/tests/ui/async-await/unnecessary-await.stderr
index 620370a6113..8d819576532 100644
--- a/tests/ui/async-await/unnecessary-await.stderr
+++ b/tests/ui/async-await/unnecessary-await.stderr
@@ -6,7 +6,7 @@ LL |     boo().await;
    |     |
    |     this call returns `()`
    |
-   = help: the trait `Future` is not implemented for `()`
+   = help: the trait `Future` is not implemented for `()`, which is required by `(): IntoFuture`
    = note: () must be a future or must implement `IntoFuture` to be awaited
    = note: required for `()` to implement `IntoFuture`
 help: remove the `.await`
@@ -28,7 +28,7 @@ LL |     e!().await;
    |         |`()` is not a future
    |         help: remove the `.await`
    |
-   = help: the trait `Future` is not implemented for `()`
+   = help: the trait `Future` is not implemented for `()`, which is required by `(): IntoFuture`
    = note: () must be a future or must implement `IntoFuture` to be awaited
    = note: required for `()` to implement `IntoFuture`
 
@@ -44,7 +44,7 @@ LL |         $expr.await
 LL |     f!(());
    |     ------ in this macro invocation
    |
-   = help: the trait `Future` is not implemented for `()`
+   = help: the trait `Future` is not implemented for `()`, which is required by `(): IntoFuture`
    = note: () must be a future or must implement `IntoFuture` to be awaited
    = note: required for `()` to implement `IntoFuture`
    = note: this error originates in the macro `f` (in Nightly builds, run with -Z macro-backtrace for more info)
@@ -58,7 +58,7 @@ LL |     for x in [] {}.await
    |                   |`()` is not a future
    |                   help: remove the `.await`
    |
-   = help: the trait `Future` is not implemented for `()`
+   = help: the trait `Future` is not implemented for `()`, which is required by `(): IntoFuture`
    = note: () must be a future or must implement `IntoFuture` to be awaited
    = note: required for `()` to implement `IntoFuture`
 
diff --git a/tests/ui/auto-traits/issue-83857-ub.stderr b/tests/ui/auto-traits/issue-83857-ub.stderr
index 80f9330eb81..97f1a603208 100644
--- a/tests/ui/auto-traits/issue-83857-ub.stderr
+++ b/tests/ui/auto-traits/issue-83857-ub.stderr
@@ -4,7 +4,7 @@ error[E0277]: `Foo<T, U>` cannot be sent between threads safely
 LL | fn generic<T, U>(v: Foo<T, U>, f: fn(<Foo<T, U> as WithAssoc>::Output) -> i32) {
    |                                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `Foo<T, U>` cannot be sent between threads safely
    |
-   = help: the trait `Send` is not implemented for `Foo<T, U>`
+   = help: the trait `Send` is not implemented for `Foo<T, U>`, which is required by `Foo<T, U>: WithAssoc`
 note: required for `Foo<T, U>` to implement `WithAssoc`
   --> $DIR/issue-83857-ub.rs:15:15
    |
diff --git a/tests/ui/auto-traits/str-contains-slice-conceptually.stderr b/tests/ui/auto-traits/str-contains-slice-conceptually.stderr
index e1dae35be00..ebd3a556e75 100644
--- a/tests/ui/auto-traits/str-contains-slice-conceptually.stderr
+++ b/tests/ui/auto-traits/str-contains-slice-conceptually.stderr
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `[u8]: AutoTrait` is not satisfied in `str`
   --> $DIR/str-contains-slice-conceptually.rs:11:22
    |
 LL |   needs_auto_trait::<str>();
-   |                      ^^^ within `str`, the trait `AutoTrait` is not implemented for `[u8]`
+   |                      ^^^ within `str`, the trait `AutoTrait` is not implemented for `[u8]`, which is required by `str: AutoTrait`
    |
    = note: `str` is considered to contain a `[u8]` slice for auto trait purposes
 note: required by a bound in `needs_auto_trait`
diff --git a/tests/ui/auto-traits/typeck-default-trait-impl-constituent-types-2.stderr b/tests/ui/auto-traits/typeck-default-trait-impl-constituent-types-2.stderr
index aa5585a5371..b7c97389912 100644
--- a/tests/ui/auto-traits/typeck-default-trait-impl-constituent-types-2.stderr
+++ b/tests/ui/auto-traits/typeck-default-trait-impl-constituent-types-2.stderr
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `MyS2: MyTrait` is not satisfied in `(MyS2, MyS)`
   --> $DIR/typeck-default-trait-impl-constituent-types-2.rs:17:18
    |
 LL |     is_mytrait::<(MyS2, MyS)>();
-   |                  ^^^^^^^^^^^ within `(MyS2, MyS)`, the trait `MyTrait` is not implemented for `MyS2`
+   |                  ^^^^^^^^^^^ within `(MyS2, MyS)`, the trait `MyTrait` is not implemented for `MyS2`, which is required by `(MyS2, MyS): MyTrait`
    |
    = note: required because it appears within the type `(MyS2, MyS)`
 note: required by a bound in `is_mytrait`
diff --git a/tests/ui/auto-traits/typeck-default-trait-impl-precedence.stderr b/tests/ui/auto-traits/typeck-default-trait-impl-precedence.stderr
index 2498af996ea..e699422ae2b 100644
--- a/tests/ui/auto-traits/typeck-default-trait-impl-precedence.stderr
+++ b/tests/ui/auto-traits/typeck-default-trait-impl-precedence.stderr
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `u32: Signed` is not satisfied
   --> $DIR/typeck-default-trait-impl-precedence.rs:19:20
    |
 LL |     is_defaulted::<&'static u32>();
-   |                    ^^^^^^^^^^^^ the trait `Signed` is not implemented for `u32`
+   |                    ^^^^^^^^^^^^ the trait `Signed` is not implemented for `u32`, which is required by `&'static u32: Defaulted`
    |
 note: required for `&'static u32` to implement `Defaulted`
   --> $DIR/typeck-default-trait-impl-precedence.rs:10:19
diff --git a/tests/ui/binop/binary-op-suggest-deref.stderr b/tests/ui/binop/binary-op-suggest-deref.stderr
index a98a2ab0706..8a226d712ff 100644
--- a/tests/ui/binop/binary-op-suggest-deref.stderr
+++ b/tests/ui/binop/binary-op-suggest-deref.stderr
@@ -27,7 +27,7 @@ error[E0277]: can't compare `&{integer}` with `{integer}`
 LL |     _ = foo == &0;
    |             ^^ no implementation for `&{integer} == {integer}`
    |
-   = help: the trait `PartialEq<{integer}>` is not implemented for `&{integer}`
+   = help: the trait `PartialEq<{integer}>` is not implemented for `&{integer}`, which is required by `&&{integer}: PartialEq<&{integer}>`
    = note: required for `&&{integer}` to implement `PartialEq<&{integer}>`
 help: consider dereferencing here
    |
@@ -65,7 +65,7 @@ error[E0277]: can't compare `&&{integer}` with `{integer}`
 LL |     _ = &&foo == &&0;
    |               ^^ no implementation for `&&{integer} == {integer}`
    |
-   = help: the trait `PartialEq<{integer}>` is not implemented for `&&{integer}`
+   = help: the trait `PartialEq<{integer}>` is not implemented for `&&{integer}`, which is required by `&&&&{integer}: PartialEq<&&{integer}>`
    = note: required for `&&&{integer}` to implement `PartialEq<&{integer}>`
    = note: 1 redundant requirement hidden
    = note: required for `&&&&{integer}` to implement `PartialEq<&&{integer}>`
@@ -119,7 +119,7 @@ error[E0277]: can't compare `{integer}` with `&{integer}`
 LL |     _ = &0 == foo;
    |            ^^ no implementation for `{integer} == &{integer}`
    |
-   = help: the trait `PartialEq<&{integer}>` is not implemented for `{integer}`
+   = help: the trait `PartialEq<&{integer}>` is not implemented for `{integer}`, which is required by `&{integer}: PartialEq<&&{integer}>`
    = note: required for `&{integer}` to implement `PartialEq<&&{integer}>`
 help: consider dereferencing here
    |
@@ -157,7 +157,7 @@ error[E0277]: can't compare `{integer}` with `&&{integer}`
 LL |     _ = &&0 == &&foo;
    |             ^^ no implementation for `{integer} == &&{integer}`
    |
-   = help: the trait `PartialEq<&&{integer}>` is not implemented for `{integer}`
+   = help: the trait `PartialEq<&&{integer}>` is not implemented for `{integer}`, which is required by `&&{integer}: PartialEq<&&&&{integer}>`
    = note: required for `&{integer}` to implement `PartialEq<&&&{integer}>`
    = note: 1 redundant requirement hidden
    = note: required for `&&{integer}` to implement `PartialEq<&&&&{integer}>`
@@ -173,7 +173,7 @@ error[E0277]: can't compare `Box<Box<{integer}>>` with `&&{integer}`
 LL |     _ = &Box::new(Box::new(42)) == &foo;
    |                                 ^^ no implementation for `Box<Box<{integer}>> == &&{integer}`
    |
-   = help: the trait `PartialEq<&&{integer}>` is not implemented for `Box<Box<{integer}>>`
+   = help: the trait `PartialEq<&&{integer}>` is not implemented for `Box<Box<{integer}>>`, which is required by `&Box<Box<{integer}>>: PartialEq<&&&{integer}>`
    = note: required for `&Box<Box<{integer}>>` to implement `PartialEq<&&&{integer}>`
 help: consider dereferencing both sides of the expression
    |
@@ -187,7 +187,7 @@ error[E0277]: can't compare `Box<{integer}>` with `&&{integer}`
 LL |     _ = &Box::new(42) == &foo;
    |                       ^^ no implementation for `Box<{integer}> == &&{integer}`
    |
-   = help: the trait `PartialEq<&&{integer}>` is not implemented for `Box<{integer}>`
+   = help: the trait `PartialEq<&&{integer}>` is not implemented for `Box<{integer}>`, which is required by `&Box<{integer}>: PartialEq<&&&{integer}>`
    = note: required for `&Box<{integer}>` to implement `PartialEq<&&&{integer}>`
 help: consider dereferencing both sides of the expression
    |
@@ -201,7 +201,7 @@ error[E0277]: can't compare `Box<Box<Box<Box<{integer}>>>>` with `&&{integer}`
 LL |     _ = &Box::new(Box::new(Box::new(Box::new(42)))) == &foo;
    |                                                     ^^ no implementation for `Box<Box<Box<Box<{integer}>>>> == &&{integer}`
    |
-   = help: the trait `PartialEq<&&{integer}>` is not implemented for `Box<Box<Box<Box<{integer}>>>>`
+   = help: the trait `PartialEq<&&{integer}>` is not implemented for `Box<Box<Box<Box<{integer}>>>>`, which is required by `&Box<Box<Box<Box<{integer}>>>>: PartialEq<&&&{integer}>`
    = note: required for `&Box<Box<Box<Box<{integer}>>>>` to implement `PartialEq<&&&{integer}>`
 help: consider dereferencing both sides of the expression
    |
@@ -215,7 +215,7 @@ error[E0277]: can't compare `&&{integer}` with `Box<Box<Box<Box<{integer}>>>>`
 LL |     _ = &foo == &Box::new(Box::new(Box::new(Box::new(42))));
    |              ^^ no implementation for `&&{integer} == Box<Box<Box<Box<{integer}>>>>`
    |
-   = help: the trait `PartialEq<Box<Box<Box<Box<{integer}>>>>>` is not implemented for `&&{integer}`
+   = help: the trait `PartialEq<Box<Box<Box<Box<{integer}>>>>>` is not implemented for `&&{integer}`, which is required by `&&&{integer}: PartialEq<&Box<Box<Box<Box<{integer}>>>>>`
    = note: required for `&&&{integer}` to implement `PartialEq<&Box<Box<Box<Box<{integer}>>>>>`
 help: consider dereferencing both sides of the expression
    |
diff --git a/tests/ui/block-result/issue-22645.stderr b/tests/ui/block-result/issue-22645.stderr
index 1064848f513..2a267ce792f 100644
--- a/tests/ui/block-result/issue-22645.stderr
+++ b/tests/ui/block-result/issue-22645.stderr
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `{integer}: Scalar` is not satisfied
   --> $DIR/issue-22645.rs:15:5
    |
 LL |   b + 3
-   |     ^ the trait `Scalar` is not implemented for `{integer}`
+   |     ^ the trait `Scalar` is not implemented for `{integer}`, which is required by `Bob: Add<_>`
    |
    = help: the trait `Scalar` is implemented for `f64`
 note: required for `Bob` to implement `Add<{integer}>`
diff --git a/tests/ui/closures/closure-move-sync.stderr b/tests/ui/closures/closure-move-sync.stderr
index 2bb26b0c0b7..6cade0c09dd 100644
--- a/tests/ui/closures/closure-move-sync.stderr
+++ b/tests/ui/closures/closure-move-sync.stderr
@@ -10,7 +10,7 @@ LL | |
 LL | |     });
    | |_____^ `std::sync::mpsc::Receiver<()>` cannot be shared between threads safely
    |
-   = help: the trait `Sync` is not implemented for `std::sync::mpsc::Receiver<()>`
+   = help: the trait `Sync` is not implemented for `std::sync::mpsc::Receiver<()>`, which is required by `{closure@$DIR/closure-move-sync.rs:6:27: 6:29}: Send`
    = note: required for `&std::sync::mpsc::Receiver<()>` to implement `Send`
 note: required because it's used within this closure
   --> $DIR/closure-move-sync.rs:6:27
diff --git a/tests/ui/closures/closure-return-type-must-be-sized.stderr b/tests/ui/closures/closure-return-type-must-be-sized.stderr
index 04ae7343bbe..167d326e26e 100644
--- a/tests/ui/closures/closure-return-type-must-be-sized.stderr
+++ b/tests/ui/closures/closure-return-type-must-be-sized.stderr
@@ -4,7 +4,7 @@ error[E0277]: the size for values of type `dyn A` cannot be known at compilation
 LL |     a::foo::<fn() -> dyn A>();
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
    |
-   = help: within `fn() -> dyn A`, the trait `Sized` is not implemented for `dyn A`
+   = help: within `fn() -> dyn A`, the trait `Sized` is not implemented for `dyn A`, which is required by `fn() -> dyn A: FnOnce()`
    = note: required because it appears within the type `fn() -> dyn A`
 
 error[E0277]: the size for values of type `dyn A` cannot be known at compilation time
@@ -13,7 +13,7 @@ error[E0277]: the size for values of type `dyn A` cannot be known at compilation
 LL |     a::bar::<fn() -> dyn A, _>();
    |              ^^^^^^^^^^^^^ doesn't have a size known at compile-time
    |
-   = help: within `fn() -> dyn A`, the trait `Sized` is not implemented for `dyn A`
+   = help: within `fn() -> dyn A`, the trait `Sized` is not implemented for `dyn A`, which is required by `fn() -> dyn A: FnOnce()`
    = note: required because it appears within the type `fn() -> dyn A`
 note: required by a bound in `a::bar`
   --> $DIR/closure-return-type-must-be-sized.rs:14:19
@@ -27,7 +27,7 @@ error[E0277]: the size for values of type `dyn A` cannot be known at compilation
 LL |     a::baz::<fn() -> dyn A>();
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
    |
-   = help: within `fn() -> dyn A`, the trait `Sized` is not implemented for `dyn A`
+   = help: within `fn() -> dyn A`, the trait `Sized` is not implemented for `dyn A`, which is required by `fn() -> dyn A: FnOnce()`
    = note: required because it appears within the type `fn() -> dyn A`
 
 error[E0277]: the size for values of type `dyn A` cannot be known at compilation time
@@ -36,7 +36,7 @@ error[E0277]: the size for values of type `dyn A` cannot be known at compilation
 LL |     b::foo::<fn() -> dyn A>();
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
    |
-   = help: within `fn() -> dyn A`, the trait `Sized` is not implemented for `dyn A`
+   = help: within `fn() -> dyn A`, the trait `Sized` is not implemented for `dyn A`, which is required by `fn() -> dyn A: FnOnce()`
    = note: required because it appears within the type `fn() -> dyn A`
 
 error[E0277]: the size for values of type `dyn A` cannot be known at compilation time
@@ -45,7 +45,7 @@ error[E0277]: the size for values of type `dyn A` cannot be known at compilation
 LL |     b::bar::<fn() -> dyn A, _>();
    |              ^^^^^^^^^^^^^ doesn't have a size known at compile-time
    |
-   = help: within `fn() -> dyn A`, the trait `Sized` is not implemented for `dyn A`
+   = help: within `fn() -> dyn A`, the trait `Sized` is not implemented for `dyn A`, which is required by `fn() -> dyn A: Fn()`
    = note: required because it appears within the type `fn() -> dyn A`
 note: required by a bound in `b::bar`
   --> $DIR/closure-return-type-must-be-sized.rs:28:19
@@ -59,7 +59,7 @@ error[E0277]: the size for values of type `dyn A` cannot be known at compilation
 LL |     b::baz::<fn() -> dyn A>();
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
    |
-   = help: within `fn() -> dyn A`, the trait `Sized` is not implemented for `dyn A`
+   = help: within `fn() -> dyn A`, the trait `Sized` is not implemented for `dyn A`, which is required by `fn() -> dyn A: FnOnce()`
    = note: required because it appears within the type `fn() -> dyn A`
 
 error[E0277]: the size for values of type `dyn A` cannot be known at compilation time
@@ -68,7 +68,7 @@ error[E0277]: the size for values of type `dyn A` cannot be known at compilation
 LL |     c::foo::<fn() -> dyn A>();
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
    |
-   = help: within `fn() -> dyn A`, the trait `Sized` is not implemented for `dyn A`
+   = help: within `fn() -> dyn A`, the trait `Sized` is not implemented for `dyn A`, which is required by `fn() -> dyn A: FnOnce()`
    = note: required because it appears within the type `fn() -> dyn A`
 
 error[E0277]: the size for values of type `dyn A` cannot be known at compilation time
@@ -77,7 +77,7 @@ error[E0277]: the size for values of type `dyn A` cannot be known at compilation
 LL |     c::bar::<fn() -> dyn A, _>();
    |              ^^^^^^^^^^^^^ doesn't have a size known at compile-time
    |
-   = help: within `fn() -> dyn A`, the trait `Sized` is not implemented for `dyn A`
+   = help: within `fn() -> dyn A`, the trait `Sized` is not implemented for `dyn A`, which is required by `fn() -> dyn A: FnMut()`
    = note: required because it appears within the type `fn() -> dyn A`
 note: required by a bound in `c::bar`
   --> $DIR/closure-return-type-must-be-sized.rs:42:19
@@ -91,7 +91,7 @@ error[E0277]: the size for values of type `dyn A` cannot be known at compilation
 LL |     c::baz::<fn() -> dyn A>();
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
    |
-   = help: within `fn() -> dyn A`, the trait `Sized` is not implemented for `dyn A`
+   = help: within `fn() -> dyn A`, the trait `Sized` is not implemented for `dyn A`, which is required by `fn() -> dyn A: FnOnce()`
    = note: required because it appears within the type `fn() -> dyn A`
 
 error: aborting due to 9 previous errors
diff --git a/tests/ui/const-generics/adt_const_params/const_param_ty_bad_empty_array.stderr b/tests/ui/const-generics/adt_const_params/const_param_ty_bad_empty_array.stderr
index 1177965d0d2..771d661f615 100644
--- a/tests/ui/const-generics/adt_const_params/const_param_ty_bad_empty_array.stderr
+++ b/tests/ui/const-generics/adt_const_params/const_param_ty_bad_empty_array.stderr
@@ -2,7 +2,7 @@ error[E0277]: `NotParam` can't be used as a const parameter type
   --> $DIR/const_param_ty_bad_empty_array.rs:10:13
    |
 LL |     check::<[NotParam; 0]>();
-   |             ^^^^^^^^^^^^^ the trait `ConstParamTy` is not implemented for `NotParam`
+   |             ^^^^^^^^^^^^^ the trait `ConstParamTy` is not implemented for `NotParam`, which is required by `[NotParam; 0]: ConstParamTy`
    |
    = note: required for `[NotParam; 0]` to implement `ConstParamTy`
 note: required by a bound in `check`
diff --git a/tests/ui/const-generics/adt_const_params/const_param_ty_generic_bounds_do_not_hold.stderr b/tests/ui/const-generics/adt_const_params/const_param_ty_generic_bounds_do_not_hold.stderr
index 86d1c94e87f..83c34c41f10 100644
--- a/tests/ui/const-generics/adt_const_params/const_param_ty_generic_bounds_do_not_hold.stderr
+++ b/tests/ui/const-generics/adt_const_params/const_param_ty_generic_bounds_do_not_hold.stderr
@@ -2,7 +2,7 @@ error[E0277]: `NotParam` can't be used as a const parameter type
   --> $DIR/const_param_ty_generic_bounds_do_not_hold.rs:10:13
    |
 LL |     check::<&NotParam>();
-   |             ^^^^^^^^^ the trait `ConstParamTy` is not implemented for `NotParam`
+   |             ^^^^^^^^^ the trait `ConstParamTy` is not implemented for `NotParam`, which is required by `&NotParam: ConstParamTy`
    |
    = note: required for `&NotParam` to implement `ConstParamTy`
 note: required by a bound in `check`
@@ -15,7 +15,7 @@ error[E0277]: `NotParam` can't be used as a const parameter type
   --> $DIR/const_param_ty_generic_bounds_do_not_hold.rs:11:13
    |
 LL |     check::<[NotParam]>();
-   |             ^^^^^^^^^^ the trait `ConstParamTy` is not implemented for `NotParam`
+   |             ^^^^^^^^^^ the trait `ConstParamTy` is not implemented for `NotParam`, which is required by `[NotParam]: ConstParamTy`
    |
    = note: required for `[NotParam]` to implement `ConstParamTy`
 note: required by a bound in `check`
@@ -28,7 +28,7 @@ error[E0277]: `NotParam` can't be used as a const parameter type
   --> $DIR/const_param_ty_generic_bounds_do_not_hold.rs:12:13
    |
 LL |     check::<[NotParam; 17]>();
-   |             ^^^^^^^^^^^^^^ the trait `ConstParamTy` is not implemented for `NotParam`
+   |             ^^^^^^^^^^^^^^ the trait `ConstParamTy` is not implemented for `NotParam`, which is required by `[NotParam; 17]: ConstParamTy`
    |
    = note: required for `[NotParam; 17]` to implement `ConstParamTy`
 note: required by a bound in `check`
diff --git a/tests/ui/const-generics/generic_const_exprs/issue-85848.stderr b/tests/ui/const-generics/generic_const_exprs/issue-85848.stderr
index 8b7120035ca..3acccba026f 100644
--- a/tests/ui/const-generics/generic_const_exprs/issue-85848.stderr
+++ b/tests/ui/const-generics/generic_const_exprs/issue-85848.stderr
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `(): _Contains<&C>` is not satisfied
   --> $DIR/issue-85848.rs:24:29
    |
 LL |     writes_to_specific_path(&cap);
-   |     ----------------------- ^^^^ the trait `_Contains<&C>` is not implemented for `()`
+   |     ----------------------- ^^^^ the trait `_Contains<&C>` is not implemented for `()`, which is required by `&C: Delegates<()>`
    |     |
    |     required by a bound introduced by this call
    |
diff --git a/tests/ui/const-generics/issues/issue-67185-2.stderr b/tests/ui/const-generics/issues/issue-67185-2.stderr
index a2e5b805368..24a2d60f2e1 100644
--- a/tests/ui/const-generics/issues/issue-67185-2.stderr
+++ b/tests/ui/const-generics/issues/issue-67185-2.stderr
@@ -26,7 +26,7 @@ error[E0277]: the trait bound `[u16; 3]: Bar` is not satisfied
   --> $DIR/issue-67185-2.rs:21:6
    |
 LL | impl Foo for FooImpl {}
-   |      ^^^ the trait `Bar` is not implemented for `[u16; 3]`
+   |      ^^^ the trait `Bar` is not implemented for `[u16; 3]`, which is required by `<u8 as Baz>::Quaks: Bar`
    |
    = help: the following other types implement trait `Bar`:
              [u16; 4]
@@ -44,7 +44,7 @@ error[E0277]: the trait bound `[[u16; 3]; 2]: Bar` is not satisfied
   --> $DIR/issue-67185-2.rs:21:6
    |
 LL | impl Foo for FooImpl {}
-   |      ^^^ the trait `Bar` is not implemented for `[[u16; 3]; 2]`
+   |      ^^^ the trait `Bar` is not implemented for `[[u16; 3]; 2]`, which is required by `[<u8 as Baz>::Quaks; 2]: Bar`
    |
    = help: the following other types implement trait `Bar`:
              [u16; 4]
diff --git a/tests/ui/consts/const-blocks/fn-call-in-non-const.stderr b/tests/ui/consts/const-blocks/fn-call-in-non-const.stderr
index b13df67b423..14bce10f787 100644
--- a/tests/ui/consts/const-blocks/fn-call-in-non-const.stderr
+++ b/tests/ui/consts/const-blocks/fn-call-in-non-const.stderr
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `Bar: Copy` is not satisfied
   --> $DIR/fn-call-in-non-const.rs:14:32
    |
 LL |     let _: [Option<Bar>; 2] = [no_copy(); 2];
-   |                                ^^^^^^^^^ the trait `Copy` is not implemented for `Bar`
+   |                                ^^^^^^^^^ the trait `Copy` is not implemented for `Bar`, which is required by `Option<Bar>: Copy`
    |
    = note: required for `Option<Bar>` to implement `Copy`
    = note: the `Copy` trait is required because this value will be copied for each element of the array
diff --git a/tests/ui/consts/const-blocks/migrate-fail.stderr b/tests/ui/consts/const-blocks/migrate-fail.stderr
index 3c116026e58..3887658f748 100644
--- a/tests/ui/consts/const-blocks/migrate-fail.stderr
+++ b/tests/ui/consts/const-blocks/migrate-fail.stderr
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `Bar: Copy` is not satisfied
   --> $DIR/migrate-fail.rs:11:38
    |
 LL |         let arr: [Option<Bar>; 2] = [x; 2];
-   |                                      ^ the trait `Copy` is not implemented for `Bar`
+   |                                      ^ the trait `Copy` is not implemented for `Bar`, which is required by `Option<Bar>: Copy`
    |
    = note: required for `Option<Bar>` to implement `Copy`
    = note: the `Copy` trait is required because this value will be copied for each element of the array
@@ -18,7 +18,7 @@ error[E0277]: the trait bound `Bar: Copy` is not satisfied
   --> $DIR/migrate-fail.rs:17:38
    |
 LL |         let arr: [Option<Bar>; 2] = [x; 2];
-   |                                      ^ the trait `Copy` is not implemented for `Bar`
+   |                                      ^ the trait `Copy` is not implemented for `Bar`, which is required by `Option<Bar>: Copy`
    |
    = note: required for `Option<Bar>` to implement `Copy`
    = note: the `Copy` trait is required because this value will be copied for each element of the array
diff --git a/tests/ui/consts/const-blocks/nll-fail.stderr b/tests/ui/consts/const-blocks/nll-fail.stderr
index ff2b62da668..a2ea833f650 100644
--- a/tests/ui/consts/const-blocks/nll-fail.stderr
+++ b/tests/ui/consts/const-blocks/nll-fail.stderr
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `Bar: Copy` is not satisfied
   --> $DIR/nll-fail.rs:11:38
    |
 LL |         let arr: [Option<Bar>; 2] = [x; 2];
-   |                                      ^ the trait `Copy` is not implemented for `Bar`
+   |                                      ^ the trait `Copy` is not implemented for `Bar`, which is required by `Option<Bar>: Copy`
    |
    = note: required for `Option<Bar>` to implement `Copy`
    = note: the `Copy` trait is required because this value will be copied for each element of the array
@@ -18,7 +18,7 @@ error[E0277]: the trait bound `Bar: Copy` is not satisfied
   --> $DIR/nll-fail.rs:17:38
    |
 LL |         let arr: [Option<Bar>; 2] = [x; 2];
-   |                                      ^ the trait `Copy` is not implemented for `Bar`
+   |                                      ^ the trait `Copy` is not implemented for `Bar`, which is required by `Option<Bar>: Copy`
    |
    = note: required for `Option<Bar>` to implement `Copy`
    = note: the `Copy` trait is required because this value will be copied for each element of the array
diff --git a/tests/ui/consts/const-blocks/trait-error.stderr b/tests/ui/consts/const-blocks/trait-error.stderr
index 36249bf3f6d..b0b1378bb7d 100644
--- a/tests/ui/consts/const-blocks/trait-error.stderr
+++ b/tests/ui/consts/const-blocks/trait-error.stderr
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `String: Copy` is not satisfied
   --> $DIR/trait-error.rs:5:6
    |
 LL |     [Foo(String::new()); 4];
-   |      ^^^^^^^^^^^^^^^^^^ the trait `Copy` is not implemented for `String`
+   |      ^^^^^^^^^^^^^^^^^^ the trait `Copy` is not implemented for `String`, which is required by `Foo<String>: Copy`
    |
 note: required for `Foo<String>` to implement `Copy`
   --> $DIR/trait-error.rs:1:10
diff --git a/tests/ui/consts/const-eval/stable-metric/ctfe-simple-loop.warn.stderr b/tests/ui/consts/const-eval/stable-metric/ctfe-simple-loop.warn.stderr
index 8eee392d15c..40fc4a876e9 100644
--- a/tests/ui/consts/const-eval/stable-metric/ctfe-simple-loop.warn.stderr
+++ b/tests/ui/consts/const-eval/stable-metric/ctfe-simple-loop.warn.stderr
@@ -40,7 +40,6 @@ help: the constant being evaluated
    |
 LL | const Y: u32 = simple_loop(35);
    | ^^^^^^^^^^^^
-   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
 
 warning: constant evaluation is taking a long time
   --> $DIR/ctfe-simple-loop.rs:9:5
diff --git a/tests/ui/consts/const-fn-in-vec.stderr b/tests/ui/consts/const-fn-in-vec.stderr
index 4593034bfae..12098e8199c 100644
--- a/tests/ui/consts/const-fn-in-vec.stderr
+++ b/tests/ui/consts/const-fn-in-vec.stderr
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `String: Copy` is not satisfied
   --> $DIR/const-fn-in-vec.rs:1:47
    |
 LL | static _MAYBE_STRINGS: [Option<String>; 5] = [None; 5];
-   |                                               ^^^^ the trait `Copy` is not implemented for `String`
+   |                                               ^^^^ the trait `Copy` is not implemented for `String`, which is required by `Option<String>: Copy`
    |
    = note: required for `Option<String>` to implement `Copy`
    = note: the `Copy` trait is required because this value will be copied for each element of the array
@@ -31,7 +31,7 @@ error[E0277]: the trait bound `String: Copy` is not satisfied
   --> $DIR/const-fn-in-vec.rs:9:48
    |
 LL |     let _maybe_strings: [Option<String>; 5] = [None; 5];
-   |                                                ^^^^ the trait `Copy` is not implemented for `String`
+   |                                                ^^^^ the trait `Copy` is not implemented for `String`, which is required by `Option<String>: Copy`
    |
    = note: required for `Option<String>` to implement `Copy`
    = note: the `Copy` trait is required because this value will be copied for each element of the array
diff --git a/tests/ui/coroutine/clone-impl.stderr b/tests/ui/coroutine/clone-impl.stderr
index 9ee011ebc36..1d4804501d8 100644
--- a/tests/ui/coroutine/clone-impl.stderr
+++ b/tests/ui/coroutine/clone-impl.stderr
@@ -5,7 +5,7 @@ LL |     let gen_clone_0 = move || {
    |                       ------- within this `{coroutine@$DIR/clone-impl.rs:36:23: 36:30}`
 ...
 LL |     check_copy(&gen_clone_0);
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^ within `{coroutine@$DIR/clone-impl.rs:36:23: 36:30}`, the trait `Copy` is not implemented for `Vec<u32>`
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^ within `{coroutine@$DIR/clone-impl.rs:36:23: 36:30}`, the trait `Copy` is not implemented for `Vec<u32>`, which is required by `{coroutine@$DIR/clone-impl.rs:36:23: 36:30}: Copy`
    |
 note: captured value does not implement `Copy`
   --> $DIR/clone-impl.rs:40:14
@@ -25,7 +25,7 @@ LL |     let gen_clone_0 = move || {
    |                       ------- within this `{coroutine@$DIR/clone-impl.rs:36:23: 36:30}`
 ...
 LL |     check_copy(&gen_clone_0);
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^ within `{coroutine@$DIR/clone-impl.rs:36:23: 36:30}`, the trait `Copy` is not implemented for `Vec<char>`
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^ within `{coroutine@$DIR/clone-impl.rs:36:23: 36:30}`, the trait `Copy` is not implemented for `Vec<char>`, which is required by `{coroutine@$DIR/clone-impl.rs:36:23: 36:30}: Copy`
    |
 note: coroutine does not implement `Copy` as this value is used across a yield
   --> $DIR/clone-impl.rs:38:9
@@ -47,7 +47,7 @@ LL |     let gen_clone_1 = move || {
    |                       ------- within this `{coroutine@$DIR/clone-impl.rs:46:23: 46:30}`
 ...
 LL |     check_copy(&gen_clone_1);
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^ within `{coroutine@$DIR/clone-impl.rs:46:23: 46:30}`, the trait `Copy` is not implemented for `Vec<u32>`
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^ within `{coroutine@$DIR/clone-impl.rs:46:23: 46:30}`, the trait `Copy` is not implemented for `Vec<u32>`, which is required by `{coroutine@$DIR/clone-impl.rs:46:23: 46:30}: Copy`
    |
 note: captured value does not implement `Copy`
   --> $DIR/clone-impl.rs:56:14
@@ -67,7 +67,7 @@ LL |     let gen_clone_1 = move || {
    |                       ------- within this `{coroutine@$DIR/clone-impl.rs:46:23: 46:30}`
 ...
 LL |     check_copy(&gen_clone_1);
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^ within `{coroutine@$DIR/clone-impl.rs:46:23: 46:30}`, the trait `Copy` is not implemented for `Vec<char>`
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^ within `{coroutine@$DIR/clone-impl.rs:46:23: 46:30}`, the trait `Copy` is not implemented for `Vec<char>`, which is required by `{coroutine@$DIR/clone-impl.rs:46:23: 46:30}: Copy`
    |
 note: coroutine does not implement `Copy` as this value is used across a yield
   --> $DIR/clone-impl.rs:52:9
@@ -90,7 +90,7 @@ LL |     let gen_non_clone = move || {
    |                         ------- within this `{coroutine@$DIR/clone-impl.rs:62:25: 62:32}`
 ...
 LL |     check_copy(&gen_non_clone);
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^ within `{coroutine@$DIR/clone-impl.rs:62:25: 62:32}`, the trait `Copy` is not implemented for `NonClone`
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^ within `{coroutine@$DIR/clone-impl.rs:62:25: 62:32}`, the trait `Copy` is not implemented for `NonClone`, which is required by `{coroutine@$DIR/clone-impl.rs:62:25: 62:32}: Copy`
    |
 note: captured value does not implement `Copy`
   --> $DIR/clone-impl.rs:64:14
@@ -115,7 +115,7 @@ LL |     let gen_non_clone = move || {
    |                         ------- within this `{coroutine@$DIR/clone-impl.rs:62:25: 62:32}`
 ...
 LL |     check_clone(&gen_non_clone);
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^ within `{coroutine@$DIR/clone-impl.rs:62:25: 62:32}`, the trait `Clone` is not implemented for `NonClone`
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^ within `{coroutine@$DIR/clone-impl.rs:62:25: 62:32}`, the trait `Clone` is not implemented for `NonClone`, which is required by `{coroutine@$DIR/clone-impl.rs:62:25: 62:32}: Clone`
    |
 note: captured value does not implement `Clone`
   --> $DIR/clone-impl.rs:64:14
diff --git a/tests/ui/coroutine/drop-tracking-parent-expression.stderr b/tests/ui/coroutine/drop-tracking-parent-expression.stderr
index a57b7ffab4d..21aa35b9579 100644
--- a/tests/ui/coroutine/drop-tracking-parent-expression.stderr
+++ b/tests/ui/coroutine/drop-tracking-parent-expression.stderr
@@ -13,7 +13,7 @@ LL | |         };
 LL | |     );
    | |_____- in this macro invocation
    |
-   = help: within `{coroutine@$DIR/drop-tracking-parent-expression.rs:17:21: 17:28}`, the trait `Send` is not implemented for `derived_drop::Client`
+   = help: within `{coroutine@$DIR/drop-tracking-parent-expression.rs:17:21: 17:28}`, the trait `Send` is not implemented for `derived_drop::Client`, which is required by `{coroutine@$DIR/drop-tracking-parent-expression.rs:17:21: 17:28}: Send`
 note: coroutine is not `Send` as this value is used across a yield
   --> $DIR/drop-tracking-parent-expression.rs:21:22
    |
@@ -53,7 +53,7 @@ LL | |         };
 LL | |     );
    | |_____- in this macro invocation
    |
-   = help: within `{coroutine@$DIR/drop-tracking-parent-expression.rs:17:21: 17:28}`, the trait `Send` is not implemented for `significant_drop::Client`
+   = help: within `{coroutine@$DIR/drop-tracking-parent-expression.rs:17:21: 17:28}`, the trait `Send` is not implemented for `significant_drop::Client`, which is required by `{coroutine@$DIR/drop-tracking-parent-expression.rs:17:21: 17:28}: Send`
 note: coroutine is not `Send` as this value is used across a yield
   --> $DIR/drop-tracking-parent-expression.rs:21:22
    |
@@ -93,7 +93,7 @@ LL | |         };
 LL | |     );
    | |_____- in this macro invocation
    |
-   = help: within `{coroutine@$DIR/drop-tracking-parent-expression.rs:17:21: 17:28}`, the trait `Send` is not implemented for `insignificant_dtor::Client`
+   = help: within `{coroutine@$DIR/drop-tracking-parent-expression.rs:17:21: 17:28}`, the trait `Send` is not implemented for `insignificant_dtor::Client`, which is required by `{coroutine@$DIR/drop-tracking-parent-expression.rs:17:21: 17:28}: Send`
 note: coroutine is not `Send` as this value is used across a yield
   --> $DIR/drop-tracking-parent-expression.rs:21:22
    |
diff --git a/tests/ui/coroutine/drop-yield-twice.stderr b/tests/ui/coroutine/drop-yield-twice.stderr
index 5766e95f088..c6a9e20b8b5 100644
--- a/tests/ui/coroutine/drop-yield-twice.stderr
+++ b/tests/ui/coroutine/drop-yield-twice.stderr
@@ -9,7 +9,7 @@ LL | |         yield;
 LL | |     })
    | |______^ coroutine is not `Send`
    |
-   = help: within `{coroutine@$DIR/drop-yield-twice.rs:7:17: 7:19}`, the trait `Send` is not implemented for `Foo`
+   = help: within `{coroutine@$DIR/drop-yield-twice.rs:7:17: 7:19}`, the trait `Send` is not implemented for `Foo`, which is required by `{coroutine@$DIR/drop-yield-twice.rs:7:17: 7:19}: Send`
 note: coroutine is not `Send` as this value is used across a yield
   --> $DIR/drop-yield-twice.rs:9:9
    |
diff --git a/tests/ui/coroutine/issue-105084.stderr b/tests/ui/coroutine/issue-105084.stderr
index 34e97752f6c..c8a6522dbd9 100644
--- a/tests/ui/coroutine/issue-105084.stderr
+++ b/tests/ui/coroutine/issue-105084.stderr
@@ -29,7 +29,7 @@ LL |     let mut g = || {
    |                 -- within this `{coroutine@$DIR/issue-105084.rs:14:17: 14:19}`
 ...
 LL |     let mut h = copy(g);
-   |                 ^^^^^^^ within `{coroutine@$DIR/issue-105084.rs:14:17: 14:19}`, the trait `Copy` is not implemented for `Box<(i32, ())>`
+   |                 ^^^^^^^ within `{coroutine@$DIR/issue-105084.rs:14:17: 14:19}`, the trait `Copy` is not implemented for `Box<(i32, ())>`, which is required by `{coroutine@$DIR/issue-105084.rs:14:17: 14:19}: Copy`
    |
 note: coroutine does not implement `Copy` as this value is used across a yield
   --> $DIR/issue-105084.rs:21:22
diff --git a/tests/ui/coroutine/issue-68112.stderr b/tests/ui/coroutine/issue-68112.stderr
index 32035003487..ded325eda54 100644
--- a/tests/ui/coroutine/issue-68112.stderr
+++ b/tests/ui/coroutine/issue-68112.stderr
@@ -4,7 +4,7 @@ error: coroutine cannot be sent between threads safely
 LL |     require_send(send_gen);
    |     ^^^^^^^^^^^^^^^^^^^^^^ coroutine is not `Send`
    |
-   = help: the trait `Sync` is not implemented for `RefCell<i32>`
+   = help: the trait `Sync` is not implemented for `RefCell<i32>`, which is required by `{coroutine@$DIR/issue-68112.rs:33:20: 33:22}: Send`
    = note: if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock` instead
 note: coroutine is not `Send` as this value is used across a yield
   --> $DIR/issue-68112.rs:36:9
@@ -26,7 +26,7 @@ error[E0277]: `RefCell<i32>` cannot be shared between threads safely
 LL |     require_send(send_gen);
    |     ^^^^^^^^^^^^^^^^^^^^^^ `RefCell<i32>` cannot be shared between threads safely
    |
-   = help: the trait `Sync` is not implemented for `RefCell<i32>`
+   = help: the trait `Sync` is not implemented for `RefCell<i32>`, which is required by `{coroutine@$DIR/issue-68112.rs:60:20: 60:22}: Send`
    = note: if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock` instead
    = note: required for `Arc<RefCell<i32>>` to implement `Send`
 note: required because it's used within this coroutine
diff --git a/tests/ui/coroutine/not-send-sync.stderr b/tests/ui/coroutine/not-send-sync.stderr
index e00c0d9158c..9228340c710 100644
--- a/tests/ui/coroutine/not-send-sync.stderr
+++ b/tests/ui/coroutine/not-send-sync.stderr
@@ -9,7 +9,7 @@ LL | |         drop(a);
 LL | |     });
    | |______^ coroutine is not `Sync`
    |
-   = help: within `{coroutine@$DIR/not-send-sync.rs:14:17: 14:19}`, the trait `Sync` is not implemented for `NotSync`
+   = help: within `{coroutine@$DIR/not-send-sync.rs:14:17: 14:19}`, the trait `Sync` is not implemented for `NotSync`, which is required by `{coroutine@$DIR/not-send-sync.rs:14:17: 14:19}: Sync`
 note: coroutine is not `Sync` as this value is used across a yield
   --> $DIR/not-send-sync.rs:17:9
    |
@@ -34,7 +34,7 @@ LL | |         drop(a);
 LL | |     });
    | |______^ coroutine is not `Send`
    |
-   = help: within `{coroutine@$DIR/not-send-sync.rs:21:17: 21:19}`, the trait `Send` is not implemented for `NotSend`
+   = help: within `{coroutine@$DIR/not-send-sync.rs:21:17: 21:19}`, the trait `Send` is not implemented for `NotSend`, which is required by `{coroutine@$DIR/not-send-sync.rs:21:17: 21:19}: Send`
 note: coroutine is not `Send` as this value is used across a yield
   --> $DIR/not-send-sync.rs:24:9
    |
diff --git a/tests/ui/coroutine/parent-expression.stderr b/tests/ui/coroutine/parent-expression.stderr
index d2c09432b3a..5b3737069e6 100644
--- a/tests/ui/coroutine/parent-expression.stderr
+++ b/tests/ui/coroutine/parent-expression.stderr
@@ -13,7 +13,7 @@ LL | |         };
 LL | |     );
    | |_____- in this macro invocation
    |
-   = help: within `{coroutine@$DIR/parent-expression.rs:17:21: 17:28}`, the trait `Send` is not implemented for `derived_drop::Client`
+   = help: within `{coroutine@$DIR/parent-expression.rs:17:21: 17:28}`, the trait `Send` is not implemented for `derived_drop::Client`, which is required by `{coroutine@$DIR/parent-expression.rs:17:21: 17:28}: Send`
 note: coroutine is not `Send` as this value is used across a yield
   --> $DIR/parent-expression.rs:21:22
    |
@@ -53,7 +53,7 @@ LL | |         };
 LL | |     );
    | |_____- in this macro invocation
    |
-   = help: within `{coroutine@$DIR/parent-expression.rs:17:21: 17:28}`, the trait `Send` is not implemented for `significant_drop::Client`
+   = help: within `{coroutine@$DIR/parent-expression.rs:17:21: 17:28}`, the trait `Send` is not implemented for `significant_drop::Client`, which is required by `{coroutine@$DIR/parent-expression.rs:17:21: 17:28}: Send`
 note: coroutine is not `Send` as this value is used across a yield
   --> $DIR/parent-expression.rs:21:22
    |
@@ -93,7 +93,7 @@ LL | |         };
 LL | |     );
    | |_____- in this macro invocation
    |
-   = help: within `{coroutine@$DIR/parent-expression.rs:17:21: 17:28}`, the trait `Send` is not implemented for `insignificant_dtor::Client`
+   = help: within `{coroutine@$DIR/parent-expression.rs:17:21: 17:28}`, the trait `Send` is not implemented for `insignificant_dtor::Client`, which is required by `{coroutine@$DIR/parent-expression.rs:17:21: 17:28}: Send`
 note: coroutine is not `Send` as this value is used across a yield
   --> $DIR/parent-expression.rs:21:22
    |
diff --git a/tests/ui/coroutine/print/coroutine-print-verbose-1.stderr b/tests/ui/coroutine/print/coroutine-print-verbose-1.stderr
index 6cf0f6e73ac..1b9ca632f0c 100644
--- a/tests/ui/coroutine/print/coroutine-print-verbose-1.stderr
+++ b/tests/ui/coroutine/print/coroutine-print-verbose-1.stderr
@@ -4,7 +4,7 @@ error: coroutine cannot be sent between threads safely
 LL |     require_send(send_gen);
    |     ^^^^^^^^^^^^^^^^^^^^^^ coroutine is not `Send`
    |
-   = help: the trait `Sync` is not implemented for `RefCell<i32>`
+   = help: the trait `Sync` is not implemented for `RefCell<i32>`, which is required by `{test1::{closure#0} upvar_tys=() witness={test1::{closure#0}}}: Send`
    = note: if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock` instead
 note: coroutine is not `Send` as this value is used across a yield
   --> $DIR/coroutine-print-verbose-1.rs:35:9
@@ -25,7 +25,7 @@ error[E0277]: `RefCell<i32>` cannot be shared between threads safely
 LL |     require_send(send_gen);
    |     ^^^^^^^^^^^^^^^^^^^^^^ `RefCell<i32>` cannot be shared between threads safely
    |
-   = help: the trait `Sync` is not implemented for `RefCell<i32>`
+   = help: the trait `Sync` is not implemented for `RefCell<i32>`, which is required by `{test2::{closure#0} upvar_tys=() witness={test2::{closure#0}}}: Send`
    = note: if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock` instead
    = note: required for `Arc<RefCell<i32>>` to implement `Send`
 note: required because it's used within this coroutine
diff --git a/tests/ui/coroutine/print/coroutine-print-verbose-2.stderr b/tests/ui/coroutine/print/coroutine-print-verbose-2.stderr
index aef48b7522b..26c9c27743c 100644
--- a/tests/ui/coroutine/print/coroutine-print-verbose-2.stderr
+++ b/tests/ui/coroutine/print/coroutine-print-verbose-2.stderr
@@ -9,7 +9,7 @@ LL | |         drop(a);
 LL | |     });
    | |______^ coroutine is not `Sync`
    |
-   = help: within `{main::{closure#0} upvar_tys=() witness={main::{closure#0}}}`, the trait `Sync` is not implemented for `NotSync`
+   = help: within `{main::{closure#0} upvar_tys=() witness={main::{closure#0}}}`, the trait `Sync` is not implemented for `NotSync`, which is required by `{main::{closure#0} upvar_tys=() witness={main::{closure#0}}}: Sync`
 note: coroutine is not `Sync` as this value is used across a yield
   --> $DIR/coroutine-print-verbose-2.rs:20:9
    |
@@ -34,7 +34,7 @@ LL | |         drop(a);
 LL | |     });
    | |______^ coroutine is not `Send`
    |
-   = help: within `{main::{closure#1} upvar_tys=() witness={main::{closure#1}}}`, the trait `Send` is not implemented for `NotSend`
+   = help: within `{main::{closure#1} upvar_tys=() witness={main::{closure#1}}}`, the trait `Send` is not implemented for `NotSend`, which is required by `{main::{closure#1} upvar_tys=() witness={main::{closure#1}}}: Send`
 note: coroutine is not `Send` as this value is used across a yield
   --> $DIR/coroutine-print-verbose-2.rs:27:9
    |
diff --git a/tests/ui/coroutine/ref-upvar-not-send.stderr b/tests/ui/coroutine/ref-upvar-not-send.stderr
index 7f18c6fba77..0f91bcf4053 100644
--- a/tests/ui/coroutine/ref-upvar-not-send.stderr
+++ b/tests/ui/coroutine/ref-upvar-not-send.stderr
@@ -10,7 +10,7 @@ LL | |         let _x = x;
 LL | |     });
    | |_____^ coroutine is not `Send`
    |
-   = help: the trait `Sync` is not implemented for `*mut ()`
+   = help: the trait `Sync` is not implemented for `*mut ()`, which is required by `{coroutine@$DIR/ref-upvar-not-send.rs:15:17: 15:24}: Send`
 note: captured value is not `Send` because `&` references cannot be sent unless their referent is `Sync`
   --> $DIR/ref-upvar-not-send.rs:19:18
    |
@@ -34,7 +34,7 @@ LL | |         let _y = y;
 LL | |     });
    | |_____^ coroutine is not `Send`
    |
-   = help: within `{coroutine@$DIR/ref-upvar-not-send.rs:23:17: 23:24}`, the trait `Send` is not implemented for `*mut ()`
+   = help: within `{coroutine@$DIR/ref-upvar-not-send.rs:23:17: 23:24}`, the trait `Send` is not implemented for `*mut ()`, which is required by `{coroutine@$DIR/ref-upvar-not-send.rs:23:17: 23:24}: Send`
 note: captured value is not `Send` because `&mut` references cannot be sent unless their referent is `Send`
   --> $DIR/ref-upvar-not-send.rs:27:18
    |
diff --git a/tests/ui/coroutine/unresolved-ct-var.stderr b/tests/ui/coroutine/unresolved-ct-var.stderr
index da2ec272f9f..8b87bac05ac 100644
--- a/tests/ui/coroutine/unresolved-ct-var.stderr
+++ b/tests/ui/coroutine/unresolved-ct-var.stderr
@@ -8,7 +8,7 @@ LL |         let s = std::array::from_fn(|_| ()).await;
    |                 |                          help: remove the `.await`
    |                 this call returns `[(); _]`
    |
-   = help: the trait `Future` is not implemented for `[(); _]`
+   = help: the trait `Future` is not implemented for `[(); _]`, which is required by `[(); _]: IntoFuture`
    = note: [(); _] must be a future or must implement `IntoFuture` to be awaited
    = note: required for `[(); _]` to implement `IntoFuture`
 
diff --git a/tests/ui/coroutine/yield-outside-coroutine-issue-78653.stderr b/tests/ui/coroutine/yield-outside-coroutine-issue-78653.stderr
index f28f8913508..8f8bec99458 100644
--- a/tests/ui/coroutine/yield-outside-coroutine-issue-78653.stderr
+++ b/tests/ui/coroutine/yield-outside-coroutine-issue-78653.stderr
@@ -10,7 +10,7 @@ error[E0277]: `{integer}` is not an iterator
 LL |     yield || for i in 0 { }
    |                       ^ `{integer}` is not an iterator
    |
-   = help: the trait `Iterator` is not implemented for `{integer}`
+   = help: the trait `Iterator` is not implemented for `{integer}`, which is required by `{integer}: IntoIterator`
    = note: if you want to iterate between `start` until a value `end`, use the exclusive range syntax `start..end` or the inclusive range syntax `start..=end`
    = note: required for `{integer}` to implement `IntoIterator`
 
diff --git a/tests/ui/derives/derives-span-Debug-enum-struct-variant.stderr b/tests/ui/derives/derives-span-Debug-enum-struct-variant.stderr
index 3f6c39bf939..b10805ac8f0 100644
--- a/tests/ui/derives/derives-span-Debug-enum-struct-variant.stderr
+++ b/tests/ui/derives/derives-span-Debug-enum-struct-variant.stderr
@@ -7,7 +7,7 @@ LL | #[derive(Debug)]
 LL |      x: Error
    |      ^^^^^^^^ `Error` cannot be formatted using `{:?}`
    |
-   = help: the trait `Debug` is not implemented for `Error`
+   = help: the trait `Debug` is not implemented for `Error`, which is required by `&Error: Debug`
    = note: add `#[derive(Debug)]` to `Error` or manually `impl Debug for Error`
    = note: this error originates in the derive macro `Debug` (in Nightly builds, run with -Z macro-backtrace for more info)
 help: consider annotating `Error` with `#[derive(Debug)]`
diff --git a/tests/ui/derives/derives-span-Debug-enum.stderr b/tests/ui/derives/derives-span-Debug-enum.stderr
index eaeffaeb849..03297443901 100644
--- a/tests/ui/derives/derives-span-Debug-enum.stderr
+++ b/tests/ui/derives/derives-span-Debug-enum.stderr
@@ -7,7 +7,7 @@ LL | #[derive(Debug)]
 LL |      Error
    |      ^^^^^ `Error` cannot be formatted using `{:?}`
    |
-   = help: the trait `Debug` is not implemented for `Error`
+   = help: the trait `Debug` is not implemented for `Error`, which is required by `&Error: Debug`
    = note: add `#[derive(Debug)]` to `Error` or manually `impl Debug for Error`
    = note: this error originates in the derive macro `Debug` (in Nightly builds, run with -Z macro-backtrace for more info)
 help: consider annotating `Error` with `#[derive(Debug)]`
diff --git a/tests/ui/derives/derives-span-Debug-struct.stderr b/tests/ui/derives/derives-span-Debug-struct.stderr
index 4a725e260de..369c0b56ac4 100644
--- a/tests/ui/derives/derives-span-Debug-struct.stderr
+++ b/tests/ui/derives/derives-span-Debug-struct.stderr
@@ -7,7 +7,7 @@ LL | struct Struct {
 LL |     x: Error
    |     ^^^^^^^^ `Error` cannot be formatted using `{:?}`
    |
-   = help: the trait `Debug` is not implemented for `Error`
+   = help: the trait `Debug` is not implemented for `Error`, which is required by `&Error: Debug`
    = note: add `#[derive(Debug)]` to `Error` or manually `impl Debug for Error`
    = note: this error originates in the derive macro `Debug` (in Nightly builds, run with -Z macro-backtrace for more info)
 help: consider annotating `Error` with `#[derive(Debug)]`
diff --git a/tests/ui/derives/derives-span-Debug-tuple-struct.stderr b/tests/ui/derives/derives-span-Debug-tuple-struct.stderr
index 2f816e1c85b..abfef9ef354 100644
--- a/tests/ui/derives/derives-span-Debug-tuple-struct.stderr
+++ b/tests/ui/derives/derives-span-Debug-tuple-struct.stderr
@@ -7,7 +7,7 @@ LL | struct Struct(
 LL |     Error
    |     ^^^^^ `Error` cannot be formatted using `{:?}`
    |
-   = help: the trait `Debug` is not implemented for `Error`
+   = help: the trait `Debug` is not implemented for `Error`, which is required by `&Error: Debug`
    = note: add `#[derive(Debug)]` to `Error` or manually `impl Debug for Error`
    = note: this error originates in the derive macro `Debug` (in Nightly builds, run with -Z macro-backtrace for more info)
 help: consider annotating `Error` with `#[derive(Debug)]`
diff --git a/tests/ui/deriving/issue-103157.stderr b/tests/ui/deriving/issue-103157.stderr
index 384899ea433..f76701860ef 100644
--- a/tests/ui/deriving/issue-103157.stderr
+++ b/tests/ui/deriving/issue-103157.stderr
@@ -5,7 +5,7 @@ LL | #[derive(PartialEq, Eq)]
    |                     -- in this derive macro expansion
 ...
 LL |     Float(Option<f64>),
-   |           ^^^^^^^^^^^ the trait `Eq` is not implemented for `f64`
+   |           ^^^^^^^^^^^ the trait `Eq` is not implemented for `f64`, which is required by `Option<f64>: Eq`
    |
    = help: the following other types implement trait `Eq`:
              isize
diff --git a/tests/ui/dst/dst-bad-deep-2.stderr b/tests/ui/dst/dst-bad-deep-2.stderr
index c7e9854340f..554e81bee10 100644
--- a/tests/ui/dst/dst-bad-deep-2.stderr
+++ b/tests/ui/dst/dst-bad-deep-2.stderr
@@ -4,7 +4,7 @@ error[E0277]: the size for values of type `[isize]` cannot be known at compilati
 LL |     let h: &(([isize],),) = &(*g,);
    |                              ^^^^^ doesn't have a size known at compile-time
    |
-   = help: within `(([isize],),)`, the trait `Sized` is not implemented for `[isize]`
+   = help: within `(([isize],),)`, the trait `Sized` is not implemented for `[isize]`, which is required by `(([isize],),): Sized`
    = note: required because it appears within the type `([isize],)`
    = note: required because it appears within the type `(([isize],),)`
    = note: tuples must have a statically known size to be initialized
diff --git a/tests/ui/dst/dst-bad-deep.stderr b/tests/ui/dst/dst-bad-deep.stderr
index 1b0f9738ab0..4f180e593f8 100644
--- a/tests/ui/dst/dst-bad-deep.stderr
+++ b/tests/ui/dst/dst-bad-deep.stderr
@@ -4,7 +4,7 @@ error[E0277]: the size for values of type `[isize]` cannot be known at compilati
 LL |     let h: &Fat<Fat<[isize]>> = &Fat { ptr: *g };
    |                                  ^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
    |
-   = help: within `Fat<Fat<[isize]>>`, the trait `Sized` is not implemented for `[isize]`
+   = help: within `Fat<Fat<[isize]>>`, the trait `Sized` is not implemented for `[isize]`, which is required by `Fat<Fat<[isize]>>: Sized`
 note: required because it appears within the type `Fat<[isize]>`
   --> $DIR/dst-bad-deep.rs:6:8
    |
diff --git a/tests/ui/error-codes/E0277-2.stderr b/tests/ui/error-codes/E0277-2.stderr
index 9a262f75590..f4e18e3bb53 100644
--- a/tests/ui/error-codes/E0277-2.stderr
+++ b/tests/ui/error-codes/E0277-2.stderr
@@ -4,7 +4,7 @@ error[E0277]: `*const u8` cannot be sent between threads safely
 LL |     is_send::<Foo>();
    |               ^^^ `*const u8` cannot be sent between threads safely
    |
-   = help: within `Foo`, the trait `Send` is not implemented for `*const u8`
+   = help: within `Foo`, the trait `Send` is not implemented for `*const u8`, which is required by `Foo: Send`
 note: required because it appears within the type `Baz`
   --> $DIR/E0277-2.rs:9:8
    |
diff --git a/tests/ui/error-codes/E0277.stderr b/tests/ui/error-codes/E0277.stderr
index 0b0d2b09720..aeb97290cf8 100644
--- a/tests/ui/error-codes/E0277.stderr
+++ b/tests/ui/error-codes/E0277.stderr
@@ -4,7 +4,7 @@ error[E0277]: the size for values of type `[u8]` cannot be known at compilation
 LL | fn f(p: Path) { }
    |      ^ doesn't have a size known at compile-time
    |
-   = help: within `Path`, the trait `Sized` is not implemented for `[u8]`
+   = help: within `Path`, the trait `Sized` is not implemented for `[u8]`, which is required by `Path: Sized`
 note: required because it appears within the type `Path`
   --> $SRC_DIR/std/src/path.rs:LL:COL
    = help: unsized fn params are gated as an unstable feature
diff --git a/tests/ui/errors/trait-bound-error-spans/blame-trait-error.stderr b/tests/ui/errors/trait-bound-error-spans/blame-trait-error.stderr
index 9228a047e87..bd4e9348227 100644
--- a/tests/ui/errors/trait-bound-error-spans/blame-trait-error.stderr
+++ b/tests/ui/errors/trait-bound-error-spans/blame-trait-error.stderr
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `Q: T3` is not satisfied
   --> $DIR/blame-trait-error.rs:53:46
    |
 LL |     want(Wrapper { value: Burrito { filling: q } });
-   |     ----                                     ^ the trait `T3` is not implemented for `Q`
+   |     ----                                     ^ the trait `T3` is not implemented for `Q`, which is required by `Wrapper<Burrito<Q>>: T1`
    |     |
    |     required by a bound introduced by this call
    |
@@ -38,7 +38,7 @@ LL |     want(Some(()));
    |     |
    |     required by a bound introduced by this call
    |
-   = help: the trait `Iterator` is not implemented for `()`
+   = help: the trait `Iterator` is not implemented for `()`, which is required by `Option<()>: T1`
    = help: the trait `T1` is implemented for `Option<It>`
 note: required for `Option<()>` to implement `T1`
   --> $DIR/blame-trait-error.rs:21:20
@@ -109,7 +109,7 @@ error[E0277]: the trait bound `Q: T3` is not satisfied
   --> $DIR/blame-trait-error.rs:65:45
    |
 LL |     want(&ExampleTuple::ExampleTupleVariant(q));
-   |     ----                                    ^ the trait `T3` is not implemented for `Q`
+   |     ----                                    ^ the trait `T3` is not implemented for `Q`, which is required by `&ExampleTuple<Q>: T1`
    |     |
    |     required by a bound introduced by this call
    |
@@ -134,7 +134,7 @@ error[E0277]: the trait bound `Q: T3` is not satisfied
   --> $DIR/blame-trait-error.rs:68:31
    |
 LL |     want(&ExampleTupleVariant(q));
-   |     ----                      ^ the trait `T3` is not implemented for `Q`
+   |     ----                      ^ the trait `T3` is not implemented for `Q`, which is required by `&ExampleTuple<Q>: T1`
    |     |
    |     required by a bound introduced by this call
    |
@@ -159,7 +159,7 @@ error[E0277]: the trait bound `Q: T3` is not satisfied
   --> $DIR/blame-trait-error.rs:71:50
    |
 LL |     want(&ExampleOtherTuple::ExampleTupleVariant(q));
-   |     ----                                         ^ the trait `T3` is not implemented for `Q`
+   |     ----                                         ^ the trait `T3` is not implemented for `Q`, which is required by `&ExampleTuple<Q>: T1`
    |     |
    |     required by a bound introduced by this call
    |
@@ -184,7 +184,7 @@ error[E0277]: the trait bound `Q: T3` is not satisfied
   --> $DIR/blame-trait-error.rs:74:44
    |
 LL |     want(&ExampleDifferentTupleVariantName(q));
-   |     ----                                   ^ the trait `T3` is not implemented for `Q`
+   |     ----                                   ^ the trait `T3` is not implemented for `Q`, which is required by `&ExampleTuple<Q>: T1`
    |     |
    |     required by a bound introduced by this call
    |
@@ -209,7 +209,7 @@ error[E0277]: the trait bound `Q: T3` is not satisfied
   --> $DIR/blame-trait-error.rs:77:45
    |
 LL |     want(&ExampleYetAnotherTupleVariantName(q));
-   |     ----                                    ^ the trait `T3` is not implemented for `Q`
+   |     ----                                    ^ the trait `T3` is not implemented for `Q`, which is required by `&ExampleTuple<Q>: T1`
    |     |
    |     required by a bound introduced by this call
    |
@@ -234,7 +234,7 @@ error[E0277]: the trait bound `Q: T3` is not satisfied
   --> $DIR/blame-trait-error.rs:80:56
    |
 LL |     want(&ExampleStruct::ExampleStructVariant { field: q });
-   |     ---- required by a bound introduced by this call   ^ the trait `T3` is not implemented for `Q`
+   |     ---- required by a bound introduced by this call   ^ the trait `T3` is not implemented for `Q`, which is required by `&ExampleStruct<Q>: T1`
    |
 note: required for `ExampleStruct<Q>` to implement `T1`
   --> $DIR/blame-trait-error.rs:45:9
@@ -257,7 +257,7 @@ error[E0277]: the trait bound `Q: T3` is not satisfied
   --> $DIR/blame-trait-error.rs:83:41
    |
 LL |     want(&ExampleStructVariant { field: q });
-   |     ----                                ^ the trait `T3` is not implemented for `Q`
+   |     ----                                ^ the trait `T3` is not implemented for `Q`, which is required by `&ExampleStruct<Q>: T1`
    |     |
    |     required by a bound introduced by this call
    |
@@ -282,7 +282,7 @@ error[E0277]: the trait bound `Q: T3` is not satisfied
   --> $DIR/blame-trait-error.rs:86:61
    |
 LL |     want(&ExampleOtherStruct::ExampleStructVariant { field: q });
-   |     ---- required by a bound introduced by this call        ^ the trait `T3` is not implemented for `Q`
+   |     ---- required by a bound introduced by this call        ^ the trait `T3` is not implemented for `Q`, which is required by `&ExampleStruct<Q>: T1`
    |
 note: required for `ExampleStruct<Q>` to implement `T1`
   --> $DIR/blame-trait-error.rs:45:9
@@ -305,7 +305,7 @@ error[E0277]: the trait bound `Q: T3` is not satisfied
   --> $DIR/blame-trait-error.rs:89:54
    |
 LL |     want(&ExampleDifferentStructVariantName { field: q });
-   |     ---- required by a bound introduced by this call ^ the trait `T3` is not implemented for `Q`
+   |     ---- required by a bound introduced by this call ^ the trait `T3` is not implemented for `Q`, which is required by `&ExampleStruct<Q>: T1`
    |
 note: required for `ExampleStruct<Q>` to implement `T1`
   --> $DIR/blame-trait-error.rs:45:9
@@ -328,7 +328,7 @@ error[E0277]: the trait bound `Q: T3` is not satisfied
   --> $DIR/blame-trait-error.rs:92:55
    |
 LL |     want(&ExampleYetAnotherStructVariantName { field: q });
-   |     ---- required by a bound introduced by this call  ^ the trait `T3` is not implemented for `Q`
+   |     ---- required by a bound introduced by this call  ^ the trait `T3` is not implemented for `Q`, which is required by `&ExampleStruct<Q>: T1`
    |
 note: required for `ExampleStruct<Q>` to implement `T1`
   --> $DIR/blame-trait-error.rs:45:9
@@ -351,7 +351,7 @@ error[E0277]: the trait bound `Q: T3` is not satisfied
   --> $DIR/blame-trait-error.rs:95:38
    |
 LL |     want(&ExampleActuallyTupleStruct(q, 0));
-   |     ----                             ^ the trait `T3` is not implemented for `Q`
+   |     ----                             ^ the trait `T3` is not implemented for `Q`, which is required by `&ExampleActuallyTupleStruct<Q>: T1`
    |     |
    |     required by a bound introduced by this call
    |
@@ -376,7 +376,7 @@ error[E0277]: the trait bound `Q: T3` is not satisfied
   --> $DIR/blame-trait-error.rs:98:43
    |
 LL |     want(&ExampleActuallyTupleStructOther(q, 0));
-   |     ----                                  ^ the trait `T3` is not implemented for `Q`
+   |     ----                                  ^ the trait `T3` is not implemented for `Q`, which is required by `&ExampleActuallyTupleStruct<Q>: T1`
    |     |
    |     required by a bound introduced by this call
    |
diff --git a/tests/ui/errors/traits/blame-trait-error-spans-on-exprs.stderr b/tests/ui/errors/traits/blame-trait-error-spans-on-exprs.stderr
index b6a24e12bcc..a2df6843f43 100644
--- a/tests/ui/errors/traits/blame-trait-error-spans-on-exprs.stderr
+++ b/tests/ui/errors/traits/blame-trait-error-spans-on-exprs.stderr
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `Q: T3` is not satisfied
   --> $DIR/blame-trait-error-spans-on-exprs.rs:81:60
    |
 LL |     want(Wrapper { value: Burrito { spicy: false, filling: q } });
-   |     ---- required by a bound introduced by this call       ^ the trait `T3` is not implemented for `Q`
+   |     ---- required by a bound introduced by this call       ^ the trait `T3` is not implemented for `Q`, which is required by `Wrapper<Burrito<Q>>: T1`
    |
 note: required for `Burrito<Q>` to implement `T2`
   --> $DIR/blame-trait-error-spans-on-exprs.rs:22:13
@@ -32,7 +32,7 @@ error[E0277]: the trait bound `Q: T3` is not satisfied
   --> $DIR/blame-trait-error-spans-on-exprs.rs:85:84
    |
 LL |     want(Wrapper { value: BurritoKinds::SmallBurrito { spicy: true, small_filling: q } });
-   |     ---- required by a bound introduced by this call                               ^ the trait `T3` is not implemented for `Q`
+   |     ---- required by a bound introduced by this call                               ^ the trait `T3` is not implemented for `Q`, which is required by `Wrapper<BurritoKinds<Q>>: T1`
    |
 note: required for `BurritoKinds<Q>` to implement `T2`
   --> $DIR/blame-trait-error-spans-on-exprs.rs:32:13
@@ -62,7 +62,7 @@ error[E0277]: the trait bound `Q: T3` is not satisfied
   --> $DIR/blame-trait-error-spans-on-exprs.rs:89:39
    |
 LL |     want(Wrapper { value: Taco(false, q) });
-   |     ----                              ^ the trait `T3` is not implemented for `Q`
+   |     ----                              ^ the trait `T3` is not implemented for `Q`, which is required by `Wrapper<Taco<Q>>: T1`
    |     |
    |     required by a bound introduced by this call
    |
@@ -94,7 +94,7 @@ error[E0277]: the trait bound `Q: T3` is not satisfied
   --> $DIR/blame-trait-error-spans-on-exprs.rs:93:53
    |
 LL |     want(Wrapper { value: TacoKinds::OneTaco(false, q) });
-   |     ----                                            ^ the trait `T3` is not implemented for `Q`
+   |     ----                                            ^ the trait `T3` is not implemented for `Q`, which is required by `Wrapper<TacoKinds<Q>>: T1`
    |     |
    |     required by a bound introduced by this call
    |
@@ -126,7 +126,7 @@ error[E0277]: the trait bound `Q: T3` is not satisfied
   --> $DIR/blame-trait-error-spans-on-exprs.rs:97:74
    |
 LL |     want(Wrapper { value: GenericBurrito { spiciness: NotSpicy, filling: q } });
-   |     ---- required by a bound introduced by this call                     ^ the trait `T3` is not implemented for `Q`
+   |     ---- required by a bound introduced by this call                     ^ the trait `T3` is not implemented for `Q`, which is required by `Wrapper<GenericBurrito<NotSpicy, Q>>: T1`
    |
 note: required for `GenericBurrito<NotSpicy, Q>` to implement `T2`
   --> $DIR/blame-trait-error-spans-on-exprs.rs:47:16
@@ -156,7 +156,7 @@ error[E0277]: the trait bound `Q: T2` is not satisfied
   --> $DIR/blame-trait-error-spans-on-exprs.rs:101:14
    |
 LL |     want((3, q));
-   |     ----     ^ the trait `T2` is not implemented for `Q`
+   |     ----     ^ the trait `T2` is not implemented for `Q`, which is required by `({integer}, Q): T1`
    |     |
    |     required by a bound introduced by this call
    |
@@ -181,7 +181,7 @@ error[E0277]: the trait bound `Q: T3` is not satisfied
   --> $DIR/blame-trait-error-spans-on-exprs.rs:105:31
    |
 LL |     want(Wrapper { value: (3, q) });
-   |     ----                      ^ the trait `T3` is not implemented for `Q`
+   |     ----                      ^ the trait `T3` is not implemented for `Q`, which is required by `Wrapper<({integer}, Q)>: T1`
    |     |
    |     required by a bound introduced by this call
    |
@@ -213,7 +213,7 @@ error[E0277]: the trait bound `Q: T3` is not satisfied
   --> $DIR/blame-trait-error-spans-on-exprs.rs:109:15
    |
 LL |     want(((3, q), 5));
-   |     ----      ^ the trait `T3` is not implemented for `Q`
+   |     ----      ^ the trait `T3` is not implemented for `Q`, which is required by `(({integer}, Q), {integer}): T1`
    |     |
    |     required by a bound introduced by this call
    |
@@ -245,7 +245,7 @@ error[E0277]: the trait bound `Q: T1` is not satisfied
   --> $DIR/blame-trait-error-spans-on-exprs.rs:112:49
    |
 LL |     want(DoubleWrapper { item: Wrapper { value: q } });
-   |     ----                                        ^ the trait `T1` is not implemented for `Q`
+   |     ----                                        ^ the trait `T1` is not implemented for `Q`, which is required by `DoubleWrapper<Q>: T1`
    |     |
    |     required by a bound introduced by this call
    |
@@ -270,7 +270,7 @@ error[E0277]: the trait bound `Q: T1` is not satisfied
   --> $DIR/blame-trait-error-spans-on-exprs.rs:115:88
    |
 LL |     want(DoubleWrapper { item: Wrapper { value: DoubleWrapper { item: Wrapper { value: q } } } });
-   |     ---- required by a bound introduced by this call                                   ^ the trait `T1` is not implemented for `Q`
+   |     ---- required by a bound introduced by this call                                   ^ the trait `T1` is not implemented for `Q`, which is required by `DoubleWrapper<DoubleWrapper<Q>>: T1`
    |
 note: required for `DoubleWrapper<Q>` to implement `T1`
   --> $DIR/blame-trait-error-spans-on-exprs.rs:72:13
@@ -295,7 +295,7 @@ error[E0277]: the trait bound `Q: T3` is not satisfied
   --> $DIR/blame-trait-error-spans-on-exprs.rs:119:27
    |
 LL |     want(Wrapper { value: AliasBurrito { spiciness: q, filling: q } });
-   |     ----                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `T3` is not implemented for `Q`
+   |     ----                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `T3` is not implemented for `Q`, which is required by `Wrapper<GenericBurrito<Q, Q>>: T1`
    |     |
    |     required by a bound introduced by this call
    |
@@ -327,7 +327,7 @@ error[E0277]: the trait bound `Q: T1` is not satisfied
   --> $DIR/blame-trait-error-spans-on-exprs.rs:122:35
    |
 LL |     want(Two { a: Two { a: (), b: q }, b: () });
-   |     ----                          ^ the trait `T1` is not implemented for `Q`
+   |     ----                          ^ the trait `T1` is not implemented for `Q`, which is required by `Two<Two<(), Q>, ()>: T1`
    |     |
    |     required by a bound introduced by this call
    |
@@ -354,7 +354,7 @@ error[E0277]: the trait bound `Q: T1` is not satisfied
 LL |     want(
    |     ---- required by a bound introduced by this call
 LL |         Two { a: Two { a: (), b: Two { a: Two { a: (), b: q }, b: () } }, b: () },
-   |                                                           ^ the trait `T1` is not implemented for `Q`
+   |                                                           ^ the trait `T1` is not implemented for `Q`, which is required by `Two<Two<(), Two<Two<(), Q>, ()>>, ()>: T1`
    |
 note: required for `Two<Two<(), Q>, ()>` to implement `T1`
   --> $DIR/blame-trait-error-spans-on-exprs.rs:66:19
@@ -379,7 +379,7 @@ error[E0277]: the trait bound `Q: T3` is not satisfied
   --> $DIR/blame-trait-error-spans-on-exprs.rs:133:44
    |
 LL |     want(&Burrito { spicy: false, filling: q });
-   |     ----                                   ^ the trait `T3` is not implemented for `Q`
+   |     ----                                   ^ the trait `T3` is not implemented for `Q`, which is required by `&Burrito<Q>: T1`
    |     |
    |     required by a bound introduced by this call
    |
diff --git a/tests/ui/extern/extern-types-unsized.stderr b/tests/ui/extern/extern-types-unsized.stderr
index a79caced111..0ae33e25b81 100644
--- a/tests/ui/extern/extern-types-unsized.stderr
+++ b/tests/ui/extern/extern-types-unsized.stderr
@@ -21,7 +21,7 @@ error[E0277]: the size for values of type `A` cannot be known at compilation tim
 LL |     assert_sized::<Foo>();
    |                    ^^^ doesn't have a size known at compile-time
    |
-   = help: within `Foo`, the trait `Sized` is not implemented for `A`
+   = help: within `Foo`, the trait `Sized` is not implemented for `A`, which is required by `Foo: Sized`
 note: required because it appears within the type `Foo`
   --> $DIR/extern-types-unsized.rs:9:8
    |
@@ -43,7 +43,7 @@ error[E0277]: the size for values of type `A` cannot be known at compilation tim
 LL |     assert_sized::<Bar<A>>();
    |                    ^^^^^^ doesn't have a size known at compile-time
    |
-   = help: within `Bar<A>`, the trait `Sized` is not implemented for `A`
+   = help: within `Bar<A>`, the trait `Sized` is not implemented for `A`, which is required by `Bar<A>: Sized`
 note: required because it appears within the type `Bar<A>`
   --> $DIR/extern-types-unsized.rs:14:8
    |
@@ -65,7 +65,7 @@ error[E0277]: the size for values of type `A` cannot be known at compilation tim
 LL |     assert_sized::<Bar<Bar<A>>>();
    |                    ^^^^^^^^^^^ doesn't have a size known at compile-time
    |
-   = help: within `Bar<Bar<A>>`, the trait `Sized` is not implemented for `A`
+   = help: within `Bar<Bar<A>>`, the trait `Sized` is not implemented for `A`, which is required by `Bar<Bar<A>>: Sized`
 note: required because it appears within the type `Bar<A>`
   --> $DIR/extern-types-unsized.rs:14:8
    |
diff --git a/tests/ui/feature-gates/feature-gate-abi_amdgpu_kernel.rs b/tests/ui/feature-gates/feature-gate-abi_amdgpu_kernel.rs
deleted file mode 100644
index 465b81d7fe3..00000000000
--- a/tests/ui/feature-gates/feature-gate-abi_amdgpu_kernel.rs
+++ /dev/null
@@ -1,30 +0,0 @@
-// compile-flags: --crate-type=rlib
-#![no_core]
-#![feature(no_core, lang_items)]
-#[lang="sized"]
-trait Sized { }
-
-extern "amdgpu-kernel" fn fu() {} //~ ERROR amdgpu-kernel ABI is experimental
-//~^ ERROR is not a supported ABI
-
-trait T {
-    extern "amdgpu-kernel" fn mu(); //~ ERROR amdgpu-kernel ABI is experimental
-    extern "amdgpu-kernel" fn dmu() {} //~ ERROR amdgpu-kernel ABI is experimental
-    //~^ ERROR is not a supported ABI
-}
-
-struct S;
-impl T for S {
-    extern "amdgpu-kernel" fn mu() {} //~ ERROR amdgpu-kernel ABI is experimental
-    //~^ ERROR is not a supported ABI
-}
-
-impl S {
-    extern "amdgpu-kernel" fn imu() {} //~ ERROR amdgpu-kernel ABI is experimental
-    //~^ ERROR is not a supported ABI
-}
-
-type TAU = extern "amdgpu-kernel" fn(); //~ ERROR amdgpu-kernel ABI is experimental
-
-extern "amdgpu-kernel" {} //~ ERROR amdgpu-kernel ABI is experimental
-//~^ ERROR is not a supported ABI
diff --git a/tests/ui/feature-gates/feature-gate-abi_amdgpu_kernel.stderr b/tests/ui/feature-gates/feature-gate-abi_amdgpu_kernel.stderr
deleted file mode 100644
index c5ae52c789b..00000000000
--- a/tests/ui/feature-gates/feature-gate-abi_amdgpu_kernel.stderr
+++ /dev/null
@@ -1,104 +0,0 @@
-error[E0658]: amdgpu-kernel ABI is experimental and subject to change
-  --> $DIR/feature-gate-abi_amdgpu_kernel.rs:7:8
-   |
-LL | extern "amdgpu-kernel" fn fu() {}
-   |        ^^^^^^^^^^^^^^^
-   |
-   = note: see issue #51575 <https://github.com/rust-lang/rust/issues/51575> for more information
-   = help: add `#![feature(abi_amdgpu_kernel)]` to the crate attributes to enable
-   = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
-
-error[E0658]: amdgpu-kernel ABI is experimental and subject to change
-  --> $DIR/feature-gate-abi_amdgpu_kernel.rs:11:12
-   |
-LL |     extern "amdgpu-kernel" fn mu();
-   |            ^^^^^^^^^^^^^^^
-   |
-   = note: see issue #51575 <https://github.com/rust-lang/rust/issues/51575> for more information
-   = help: add `#![feature(abi_amdgpu_kernel)]` to the crate attributes to enable
-   = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
-
-error[E0658]: amdgpu-kernel ABI is experimental and subject to change
-  --> $DIR/feature-gate-abi_amdgpu_kernel.rs:12:12
-   |
-LL |     extern "amdgpu-kernel" fn dmu() {}
-   |            ^^^^^^^^^^^^^^^
-   |
-   = note: see issue #51575 <https://github.com/rust-lang/rust/issues/51575> for more information
-   = help: add `#![feature(abi_amdgpu_kernel)]` to the crate attributes to enable
-   = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
-
-error[E0658]: amdgpu-kernel ABI is experimental and subject to change
-  --> $DIR/feature-gate-abi_amdgpu_kernel.rs:18:12
-   |
-LL |     extern "amdgpu-kernel" fn mu() {}
-   |            ^^^^^^^^^^^^^^^
-   |
-   = note: see issue #51575 <https://github.com/rust-lang/rust/issues/51575> for more information
-   = help: add `#![feature(abi_amdgpu_kernel)]` to the crate attributes to enable
-   = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
-
-error[E0658]: amdgpu-kernel ABI is experimental and subject to change
-  --> $DIR/feature-gate-abi_amdgpu_kernel.rs:23:12
-   |
-LL |     extern "amdgpu-kernel" fn imu() {}
-   |            ^^^^^^^^^^^^^^^
-   |
-   = note: see issue #51575 <https://github.com/rust-lang/rust/issues/51575> for more information
-   = help: add `#![feature(abi_amdgpu_kernel)]` to the crate attributes to enable
-   = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
-
-error[E0658]: amdgpu-kernel ABI is experimental and subject to change
-  --> $DIR/feature-gate-abi_amdgpu_kernel.rs:27:19
-   |
-LL | type TAU = extern "amdgpu-kernel" fn();
-   |                   ^^^^^^^^^^^^^^^
-   |
-   = note: see issue #51575 <https://github.com/rust-lang/rust/issues/51575> for more information
-   = help: add `#![feature(abi_amdgpu_kernel)]` to the crate attributes to enable
-   = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
-
-error[E0658]: amdgpu-kernel ABI is experimental and subject to change
-  --> $DIR/feature-gate-abi_amdgpu_kernel.rs:29:8
-   |
-LL | extern "amdgpu-kernel" {}
-   |        ^^^^^^^^^^^^^^^
-   |
-   = note: see issue #51575 <https://github.com/rust-lang/rust/issues/51575> for more information
-   = help: add `#![feature(abi_amdgpu_kernel)]` to the crate attributes to enable
-   = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
-
-error[E0570]: `"amdgpu-kernel"` is not a supported ABI for the current target
-  --> $DIR/feature-gate-abi_amdgpu_kernel.rs:29:1
-   |
-LL | extern "amdgpu-kernel" {}
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^
-
-error[E0570]: `"amdgpu-kernel"` is not a supported ABI for the current target
-  --> $DIR/feature-gate-abi_amdgpu_kernel.rs:7:1
-   |
-LL | extern "amdgpu-kernel" fn fu() {}
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
-error[E0570]: `"amdgpu-kernel"` is not a supported ABI for the current target
-  --> $DIR/feature-gate-abi_amdgpu_kernel.rs:12:5
-   |
-LL |     extern "amdgpu-kernel" fn dmu() {}
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
-error[E0570]: `"amdgpu-kernel"` is not a supported ABI for the current target
-  --> $DIR/feature-gate-abi_amdgpu_kernel.rs:18:5
-   |
-LL |     extern "amdgpu-kernel" fn mu() {}
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
-error[E0570]: `"amdgpu-kernel"` is not a supported ABI for the current target
-  --> $DIR/feature-gate-abi_amdgpu_kernel.rs:23:5
-   |
-LL |     extern "amdgpu-kernel" fn imu() {}
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
-error: aborting due to 12 previous errors
-
-Some errors have detailed explanations: E0570, E0658.
-For more information about an error, try `rustc --explain E0570`.
diff --git a/tests/ui/feature-gates/feature-gate-trivial_bounds.stderr b/tests/ui/feature-gates/feature-gate-trivial_bounds.stderr
index 1b87ebd9f20..7fc726409ce 100644
--- a/tests/ui/feature-gates/feature-gate-trivial_bounds.stderr
+++ b/tests/ui/feature-gates/feature-gate-trivial_bounds.stderr
@@ -94,7 +94,7 @@ error[E0277]: the size for values of type `(dyn A + 'static)` cannot be known at
 LL | fn unsized_local() where Dst<dyn A>: Sized {
    |                          ^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
    |
-   = help: within `Dst<(dyn A + 'static)>`, the trait `Sized` is not implemented for `(dyn A + 'static)`
+   = help: within `Dst<(dyn A + 'static)>`, the trait `Sized` is not implemented for `(dyn A + 'static)`, which is required by `Dst<(dyn A + 'static)>: Sized`
 note: required because it appears within the type `Dst<(dyn A + 'static)>`
   --> $DIR/feature-gate-trivial_bounds.rs:48:8
    |
diff --git a/tests/ui/fmt/ifmt-unimpl.stderr b/tests/ui/fmt/ifmt-unimpl.stderr
index c0650ff17c5..58531c61bbe 100644
--- a/tests/ui/fmt/ifmt-unimpl.stderr
+++ b/tests/ui/fmt/ifmt-unimpl.stderr
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `str: UpperHex` is not satisfied
   --> $DIR/ifmt-unimpl.rs:2:21
    |
 LL |     format!("{:X}", "3");
-   |              ----   ^^^ the trait `UpperHex` is not implemented for `str`
+   |              ----   ^^^ the trait `UpperHex` is not implemented for `str`, which is required by `&str: UpperHex`
    |              |
    |              required by a bound introduced by this call
    |
diff --git a/tests/ui/fmt/send-sync.stderr b/tests/ui/fmt/send-sync.stderr
index 6c9c7941eb3..aa377553c50 100644
--- a/tests/ui/fmt/send-sync.stderr
+++ b/tests/ui/fmt/send-sync.stderr
@@ -6,7 +6,7 @@ LL |     send(format_args!("{:?}", c));
    |     |
    |     required by a bound introduced by this call
    |
-   = help: within `[core::fmt::rt::Argument<'_>]`, the trait `Sync` is not implemented for `core::fmt::rt::Opaque`
+   = help: within `[core::fmt::rt::Argument<'_>]`, the trait `Sync` is not implemented for `core::fmt::rt::Opaque`, which is required by `Arguments<'_>: Send`
    = note: required because it appears within the type `&core::fmt::rt::Opaque`
 note: required because it appears within the type `core::fmt::rt::Argument<'_>`
   --> $SRC_DIR/core/src/fmt/rt.rs:LL:COL
@@ -28,7 +28,7 @@ LL |     sync(format_args!("{:?}", c));
    |     |
    |     required by a bound introduced by this call
    |
-   = help: within `Arguments<'_>`, the trait `Sync` is not implemented for `core::fmt::rt::Opaque`
+   = help: within `Arguments<'_>`, the trait `Sync` is not implemented for `core::fmt::rt::Opaque`, which is required by `Arguments<'_>: Sync`
    = note: required because it appears within the type `&core::fmt::rt::Opaque`
 note: required because it appears within the type `core::fmt::rt::Argument<'_>`
   --> $SRC_DIR/core/src/fmt/rt.rs:LL:COL
diff --git a/tests/ui/for/for-c-in-str.stderr b/tests/ui/for/for-c-in-str.stderr
index 475cf8c8874..2544df64629 100644
--- a/tests/ui/for/for-c-in-str.stderr
+++ b/tests/ui/for/for-c-in-str.stderr
@@ -4,7 +4,7 @@ error[E0277]: `&str` is not an iterator
 LL |     for c in "asdf" {
    |              ^^^^^^ `&str` is not an iterator; try calling `.chars()` or `.bytes()`
    |
-   = help: the trait `Iterator` is not implemented for `&str`
+   = help: the trait `Iterator` is not implemented for `&str`, which is required by `&str: IntoIterator`
    = note: required for `&str` to implement `IntoIterator`
 
 error: aborting due to 1 previous error
diff --git a/tests/ui/for/for-loop-bogosity.stderr b/tests/ui/for/for-loop-bogosity.stderr
index 194a2fa08ce..143e4a4efd1 100644
--- a/tests/ui/for/for-loop-bogosity.stderr
+++ b/tests/ui/for/for-loop-bogosity.stderr
@@ -4,7 +4,7 @@ error[E0277]: `MyStruct` is not an iterator
 LL |     for x in bogus {
    |              ^^^^^ `MyStruct` is not an iterator
    |
-   = help: the trait `Iterator` is not implemented for `MyStruct`
+   = help: the trait `Iterator` is not implemented for `MyStruct`, which is required by `MyStruct: IntoIterator`
    = note: required for `MyStruct` to implement `IntoIterator`
 
 error: aborting due to 1 previous error
diff --git a/tests/ui/function-pointer/unsized-ret.stderr b/tests/ui/function-pointer/unsized-ret.stderr
index 66116273ff4..81d603f4b20 100644
--- a/tests/ui/function-pointer/unsized-ret.stderr
+++ b/tests/ui/function-pointer/unsized-ret.stderr
@@ -4,7 +4,7 @@ error[E0277]: the size for values of type `str` cannot be known at compilation t
 LL |     foo::<fn() -> str, _>(None, ());
    |           ^^^^^^^^^^^ doesn't have a size known at compile-time
    |
-   = help: within `fn() -> str`, the trait `Sized` is not implemented for `str`
+   = help: within `fn() -> str`, the trait `Sized` is not implemented for `str`, which is required by `fn() -> str: Fn<_>`
    = note: required because it appears within the type `fn() -> str`
 note: required by a bound in `foo`
   --> $DIR/unsized-ret.rs:5:11
@@ -18,7 +18,7 @@ error[E0277]: the size for values of type `(dyn std::fmt::Display + 'a)` cannot
 LL |     foo::<for<'a> fn(&'a ()) -> (dyn std::fmt::Display + 'a), _>(None, (&(),));
    |           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
    |
-   = help: within `for<'a> fn(&'a ()) -> (dyn std::fmt::Display + 'a)`, the trait `for<'a> Sized` is not implemented for `(dyn std::fmt::Display + 'a)`
+   = help: within `for<'a> fn(&'a ()) -> (dyn std::fmt::Display + 'a)`, the trait `for<'a> Sized` is not implemented for `(dyn std::fmt::Display + 'a)`, which is required by `for<'a> fn(&'a ()) -> (dyn std::fmt::Display + 'a): Fn<_>`
    = note: required because it appears within the type `for<'a> fn(&'a ()) -> (dyn std::fmt::Display + 'a)`
 note: required by a bound in `foo`
   --> $DIR/unsized-ret.rs:5:11
diff --git a/tests/ui/generic-associated-types/assume-gat-normalization-for-nested-goals.stderr b/tests/ui/generic-associated-types/assume-gat-normalization-for-nested-goals.stderr
index 685c2794967..314a5509da8 100644
--- a/tests/ui/generic-associated-types/assume-gat-normalization-for-nested-goals.stderr
+++ b/tests/ui/generic-associated-types/assume-gat-normalization-for-nested-goals.stderr
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `<Self as Foo>::Bar<()>: Eq<i32>` is not satisfied
   --> $DIR/assume-gat-normalization-for-nested-goals.rs:6:30
    |
 LL |     type Bar<T>: Baz<Self> = i32;
-   |                              ^^^ the trait `Eq<i32>` is not implemented for `<Self as Foo>::Bar<()>`
+   |                              ^^^ the trait `Eq<i32>` is not implemented for `<Self as Foo>::Bar<()>`, which is required by `i32: Baz<Self>`
    |
 note: required for `i32` to implement `Baz<Self>`
   --> $DIR/assume-gat-normalization-for-nested-goals.rs:13:23
diff --git a/tests/ui/generic-associated-types/impl_bounds.stderr b/tests/ui/generic-associated-types/impl_bounds.stderr
index 261070d1db4..c3b119e2144 100644
--- a/tests/ui/generic-associated-types/impl_bounds.stderr
+++ b/tests/ui/generic-associated-types/impl_bounds.stderr
@@ -25,7 +25,7 @@ error[E0277]: the trait bound `T: Copy` is not satisfied
   --> $DIR/impl_bounds.rs:18:33
    |
 LL |     type C = String where Self: Copy;
-   |                                 ^^^^ the trait `Copy` is not implemented for `T`
+   |                                 ^^^^ the trait `Copy` is not implemented for `T`, which is required by `Fooy<T>: Copy`
    |
 note: required for `Fooy<T>` to implement `Copy`
   --> $DIR/impl_bounds.rs:10:10
@@ -50,7 +50,7 @@ error[E0277]: the trait bound `T: Copy` is not satisfied
   --> $DIR/impl_bounds.rs:20:24
    |
 LL |     fn d() where Self: Copy {}
-   |                        ^^^^ the trait `Copy` is not implemented for `T`
+   |                        ^^^^ the trait `Copy` is not implemented for `T`, which is required by `Fooy<T>: Copy`
    |
 note: required for `Fooy<T>` to implement `Copy`
   --> $DIR/impl_bounds.rs:10:10
diff --git a/tests/ui/generic-associated-types/issue-101020.stderr b/tests/ui/generic-associated-types/issue-101020.stderr
index 9c3753c2d18..7faab4e5274 100644
--- a/tests/ui/generic-associated-types/issue-101020.stderr
+++ b/tests/ui/generic-associated-types/issue-101020.stderr
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `for<'a> &'a mut (): Foo<&'a mut ()>` is not satis
   --> $DIR/issue-101020.rs:31:22
    |
 LL |     (&mut EmptyIter).consume(());
-   |                      ^^^^^^^ the trait `for<'a> Foo<&'a mut ()>` is not implemented for `&'a mut ()`
+   |                      ^^^^^^^ the trait `for<'a> Foo<&'a mut ()>` is not implemented for `&'a mut ()`, which is required by `for<'a> &'a mut (): FuncInput<'a, &'a mut ()>`
    |
 help: this trait has no implementations, consider adding one
   --> $DIR/issue-101020.rs:28:1
diff --git a/tests/ui/generic-associated-types/issue-74824.stderr b/tests/ui/generic-associated-types/issue-74824.stderr
index e5638d90ee8..942d9583be1 100644
--- a/tests/ui/generic-associated-types/issue-74824.stderr
+++ b/tests/ui/generic-associated-types/issue-74824.stderr
@@ -14,7 +14,7 @@ error[E0277]: the trait bound `T: Clone` is not satisfied
   --> $DIR/issue-74824.rs:6:26
    |
 LL |     type Copy<T>: Copy = Box<T>;
-   |                          ^^^^^^ the trait `Clone` is not implemented for `T`
+   |                          ^^^^^^ the trait `Clone` is not implemented for `T`, which is required by `<Self as UnsafeCopy>::Copy<T>: Copy`
    |
    = note: required for `Box<T>` to implement `Clone`
    = note: required for `<Self as UnsafeCopy>::Copy<T>` to implement `Copy`
diff --git a/tests/ui/higher-ranked/trait-bounds/normalize-under-binder/issue-89118.stderr b/tests/ui/higher-ranked/trait-bounds/normalize-under-binder/issue-89118.stderr
index 7fe803550bd..761fd9045a1 100644
--- a/tests/ui/higher-ranked/trait-bounds/normalize-under-binder/issue-89118.stderr
+++ b/tests/ui/higher-ranked/trait-bounds/normalize-under-binder/issue-89118.stderr
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `for<'a> &'a (): BufferMut` is not satisfied
   --> $DIR/issue-89118.rs:19:8
    |
 LL |     C: StackContext,
-   |        ^^^^^^^^^^^^ the trait `for<'a> BufferMut` is not implemented for `&'a ()`
+   |        ^^^^^^^^^^^^ the trait `for<'a> BufferMut` is not implemented for `&'a ()`, which is required by `for<'a> Ctx<()>: BufferUdpStateContext<&'a ()>`
    |
 help: this trait has no implementations, consider adding one
   --> $DIR/issue-89118.rs:1:1
@@ -29,7 +29,7 @@ error[E0277]: the trait bound `for<'a> &'a (): BufferMut` is not satisfied
   --> $DIR/issue-89118.rs:29:9
    |
 LL | impl<C> EthernetWorker<C> {}
-   |         ^^^^^^^^^^^^^^^^^ the trait `for<'a> BufferMut` is not implemented for `&'a ()`
+   |         ^^^^^^^^^^^^^^^^^ the trait `for<'a> BufferMut` is not implemented for `&'a ()`, which is required by `for<'a> Ctx<()>: BufferUdpStateContext<&'a ()>`
    |
 help: this trait has no implementations, consider adding one
   --> $DIR/issue-89118.rs:1:1
@@ -56,7 +56,7 @@ error[E0277]: the trait bound `for<'a> &'a (): BufferMut` is not satisfied
   --> $DIR/issue-89118.rs:22:20
    |
 LL |     type Handler = Ctx<C::Dispatcher>;
-   |                    ^^^^^^^^^^^^^^^^^^ the trait `for<'a> BufferMut` is not implemented for `&'a ()`
+   |                    ^^^^^^^^^^^^^^^^^^ the trait `for<'a> BufferMut` is not implemented for `&'a ()`, which is required by `for<'a> Ctx<()>: BufferUdpStateContext<&'a ()>`
    |
 help: this trait has no implementations, consider adding one
   --> $DIR/issue-89118.rs:1:1
diff --git a/tests/ui/impl-trait/auto-trait-leak2.stderr b/tests/ui/impl-trait/auto-trait-leak2.stderr
index 52fa28145d6..1fcde0372fc 100644
--- a/tests/ui/impl-trait/auto-trait-leak2.stderr
+++ b/tests/ui/impl-trait/auto-trait-leak2.stderr
@@ -9,7 +9,7 @@ LL |     send(before());
    |     |
    |     required by a bound introduced by this call
    |
-   = help: within `impl Fn(i32)`, the trait `Send` is not implemented for `Rc<Cell<i32>>`
+   = help: within `impl Fn(i32)`, the trait `Send` is not implemented for `Rc<Cell<i32>>`, which is required by `impl Fn(i32): Send`
 note: required because it's used within this closure
   --> $DIR/auto-trait-leak2.rs:10:5
    |
@@ -37,7 +37,7 @@ LL |     send(after());
 LL | fn after() -> impl Fn(i32) {
    |               ------------ within this `impl Fn(i32)`
    |
-   = help: within `impl Fn(i32)`, the trait `Send` is not implemented for `Rc<Cell<i32>>`
+   = help: within `impl Fn(i32)`, the trait `Send` is not implemented for `Rc<Cell<i32>>`, which is required by `impl Fn(i32): Send`
 note: required because it's used within this closure
   --> $DIR/auto-trait-leak2.rs:38:5
    |
diff --git a/tests/ui/impl-trait/dyn-trait-return-should-be-impl-trait.stderr b/tests/ui/impl-trait/dyn-trait-return-should-be-impl-trait.stderr
index 9cc199d1e0e..f25269ca032 100644
--- a/tests/ui/impl-trait/dyn-trait-return-should-be-impl-trait.stderr
+++ b/tests/ui/impl-trait/dyn-trait-return-should-be-impl-trait.stderr
@@ -16,7 +16,7 @@ LL | fn fuz() -> (usize, Trait) { (42, Struct) }
    |             |
    |             doesn't have a size known at compile-time
    |
-   = help: within `(usize, (dyn Trait + 'static))`, the trait `Sized` is not implemented for `(dyn Trait + 'static)`
+   = help: within `(usize, (dyn Trait + 'static))`, the trait `Sized` is not implemented for `(dyn Trait + 'static)`, which is required by `(usize, (dyn Trait + 'static)): Sized`
    = note: required because it appears within the type `(usize, (dyn Trait + 'static))`
    = note: the return type of a function must have a statically known size
 
@@ -38,7 +38,7 @@ LL | fn bar() -> (usize, dyn Trait) { (42, Struct) }
    |             |
    |             doesn't have a size known at compile-time
    |
-   = help: within `(usize, (dyn Trait + 'static))`, the trait `Sized` is not implemented for `(dyn Trait + 'static)`
+   = help: within `(usize, (dyn Trait + 'static))`, the trait `Sized` is not implemented for `(dyn Trait + 'static)`, which is required by `(usize, (dyn Trait + 'static)): Sized`
    = note: required because it appears within the type `(usize, (dyn Trait + 'static))`
    = note: the return type of a function must have a statically known size
 
diff --git a/tests/ui/impl-trait/impl_trait_projections.stderr b/tests/ui/impl-trait/impl_trait_projections.stderr
index 700aff36aa5..421afc96eed 100644
--- a/tests/ui/impl-trait/impl_trait_projections.stderr
+++ b/tests/ui/impl-trait/impl_trait_projections.stderr
@@ -32,7 +32,7 @@ error[E0277]: the trait bound `impl Debug: Step` is not satisfied
   --> $DIR/impl_trait_projections.rs:26:8
    |
 LL |     -> <::std::ops::Range<impl Debug> as Iterator>::Item
-   |        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Step` is not implemented for `impl Debug`
+   |        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Step` is not implemented for `impl Debug`, which is required by `std::ops::Range<impl Debug>: Iterator`
    |
    = help: the following other types implement trait `Step`:
              char
@@ -53,7 +53,7 @@ LL | / {
 LL | |
 LL | |     (1i32..100).next().unwrap()
 LL | | }
-   | |_^ the trait `Step` is not implemented for `impl Debug`
+   | |_^ the trait `Step` is not implemented for `impl Debug`, which is required by `std::ops::Range<impl Debug>: Iterator`
    |
    = help: the following other types implement trait `Step`:
              char
diff --git a/tests/ui/impl-trait/issue-55872-1.stderr b/tests/ui/impl-trait/issue-55872-1.stderr
index 8912cce1b4b..0c86824e622 100644
--- a/tests/ui/impl-trait/issue-55872-1.stderr
+++ b/tests/ui/impl-trait/issue-55872-1.stderr
@@ -11,7 +11,7 @@ error[E0277]: the trait bound `S: Copy` is not satisfied in `(S, T)`
   --> $DIR/issue-55872-1.rs:12:29
    |
 LL |     fn foo<T: Default>() -> Self::E {
-   |                             ^^^^^^^ within `(S, T)`, the trait `Copy` is not implemented for `S`
+   |                             ^^^^^^^ within `(S, T)`, the trait `Copy` is not implemented for `S`, which is required by `(S, T): Copy`
    |
    = note: required because it appears within the type `(S, T)`
 help: consider further restricting this bound
@@ -23,7 +23,7 @@ error[E0277]: the trait bound `T: Copy` is not satisfied in `(S, T)`
   --> $DIR/issue-55872-1.rs:12:29
    |
 LL |     fn foo<T: Default>() -> Self::E {
-   |                             ^^^^^^^ within `(S, T)`, the trait `Copy` is not implemented for `T`
+   |                             ^^^^^^^ within `(S, T)`, the trait `Copy` is not implemented for `T`, which is required by `(S, T): Copy`
    |
    = note: required because it appears within the type `(S, T)`
 help: consider further restricting this bound
diff --git a/tests/ui/impl-trait/nested_impl_trait.stderr b/tests/ui/impl-trait/nested_impl_trait.stderr
index 31c3e0c9013..83d1347aff4 100644
--- a/tests/ui/impl-trait/nested_impl_trait.stderr
+++ b/tests/ui/impl-trait/nested_impl_trait.stderr
@@ -46,7 +46,7 @@ error[E0277]: the trait bound `impl Debug: From<impl Into<u32>>` is not satisfie
   --> $DIR/nested_impl_trait.rs:6:46
    |
 LL | fn bad_in_ret_position(x: impl Into<u32>) -> impl Into<impl Debug> { x }
-   |                                              ^^^^^^^^^^^^^^^^^^^^^ the trait `From<impl Into<u32>>` is not implemented for `impl Debug`
+   |                                              ^^^^^^^^^^^^^^^^^^^^^ the trait `From<impl Into<u32>>` is not implemented for `impl Debug`, which is required by `impl Into<u32>: Into<impl Debug>`
    |
    = help: the trait `Into<U>` is implemented for `T`
    = note: required for `impl Into<u32>` to implement `Into<impl Debug>`
@@ -55,7 +55,7 @@ error[E0277]: the trait bound `impl Debug: From<impl Into<u32>>` is not satisfie
   --> $DIR/nested_impl_trait.rs:19:34
    |
 LL |     fn bad(x: impl Into<u32>) -> impl Into<impl Debug> { x }
-   |                                  ^^^^^^^^^^^^^^^^^^^^^ the trait `From<impl Into<u32>>` is not implemented for `impl Debug`
+   |                                  ^^^^^^^^^^^^^^^^^^^^^ the trait `From<impl Into<u32>>` is not implemented for `impl Debug`, which is required by `impl Into<u32>: Into<impl Debug>`
    |
    = help: the trait `Into<U>` is implemented for `T`
    = note: required for `impl Into<u32>` to implement `Into<impl Debug>`
diff --git a/tests/ui/imports/ambiguous-9.stderr b/tests/ui/imports/ambiguous-9.stderr
index 2731ed2ba86..6c7d79174da 100644
--- a/tests/ui/imports/ambiguous-9.stderr
+++ b/tests/ui/imports/ambiguous-9.stderr
@@ -60,7 +60,6 @@ note: `date_range` could also refer to the function imported here
 LL | use prelude::*;
    |     ^^^^^^^^^^
    = help: consider adding an explicit import of `date_range` to disambiguate
-   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
 
 warning: 4 warnings emitted
 
diff --git a/tests/ui/indexing/index-help.stderr b/tests/ui/indexing/index-help.stderr
index 4ec28ddf871..1291bf2a461 100644
--- a/tests/ui/indexing/index-help.stderr
+++ b/tests/ui/indexing/index-help.stderr
@@ -4,7 +4,7 @@ error[E0277]: the type `[{integer}]` cannot be indexed by `i32`
 LL |     x[0i32];
    |       ^^^^ slice indices are of type `usize` or ranges of `usize`
    |
-   = help: the trait `SliceIndex<[{integer}]>` is not implemented for `i32`
+   = help: the trait `SliceIndex<[{integer}]>` is not implemented for `i32`, which is required by `Vec<{integer}>: Index<_>`
    = help: the trait `SliceIndex<[{integer}]>` is implemented for `usize`
    = help: for that trait implementation, expected `usize`, found `i32`
    = note: required for `Vec<{integer}>` to implement `Index<i32>`
diff --git a/tests/ui/indexing/indexing-requires-a-uint.stderr b/tests/ui/indexing/indexing-requires-a-uint.stderr
index 3041c2c99a1..38e7881dcc6 100644
--- a/tests/ui/indexing/indexing-requires-a-uint.stderr
+++ b/tests/ui/indexing/indexing-requires-a-uint.stderr
@@ -4,7 +4,7 @@ error[E0277]: the type `[{integer}]` cannot be indexed by `u8`
 LL |     [0][0u8];
    |         ^^^ slice indices are of type `usize` or ranges of `usize`
    |
-   = help: the trait `SliceIndex<[{integer}]>` is not implemented for `u8`
+   = help: the trait `SliceIndex<[{integer}]>` is not implemented for `u8`, which is required by `[{integer}; 1]: Index<_>`
    = help: the trait `SliceIndex<[{integer}]>` is implemented for `usize`
    = help: for that trait implementation, expected `usize`, found `u8`
    = note: required for `[{integer}]` to implement `Index<u8>`
diff --git a/tests/ui/indexing/point-at-index-for-obligation-failure.stderr b/tests/ui/indexing/point-at-index-for-obligation-failure.stderr
index 4cced22789f..df4d7cc0683 100644
--- a/tests/ui/indexing/point-at-index-for-obligation-failure.stderr
+++ b/tests/ui/indexing/point-at-index-for-obligation-failure.stderr
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `String: Borrow<&str>` is not satisfied
   --> $DIR/point-at-index-for-obligation-failure.rs:5:9
    |
 LL |         &s
-   |         ^^ the trait `Borrow<&str>` is not implemented for `String`
+   |         ^^ the trait `Borrow<&str>` is not implemented for `String`, which is required by `HashMap<String, String>: Index<&_>`
    |
    = help: the trait `Borrow<str>` is implemented for `String`
    = help: for that trait implementation, expected `str`, found `&str`
diff --git a/tests/ui/integral-indexing.stderr b/tests/ui/integral-indexing.stderr
index 97e658617cf..ad2c3af424b 100644
--- a/tests/ui/integral-indexing.stderr
+++ b/tests/ui/integral-indexing.stderr
@@ -4,7 +4,7 @@ error[E0277]: the type `[isize]` cannot be indexed by `u8`
 LL |     v[3u8];
    |       ^^^ slice indices are of type `usize` or ranges of `usize`
    |
-   = help: the trait `SliceIndex<[isize]>` is not implemented for `u8`
+   = help: the trait `SliceIndex<[isize]>` is not implemented for `u8`, which is required by `Vec<isize>: Index<_>`
    = help: the trait `SliceIndex<[isize]>` is implemented for `usize`
    = help: for that trait implementation, expected `usize`, found `u8`
    = note: required for `Vec<isize>` to implement `Index<u8>`
@@ -15,7 +15,7 @@ error[E0277]: the type `[isize]` cannot be indexed by `i8`
 LL |     v[3i8];
    |       ^^^ slice indices are of type `usize` or ranges of `usize`
    |
-   = help: the trait `SliceIndex<[isize]>` is not implemented for `i8`
+   = help: the trait `SliceIndex<[isize]>` is not implemented for `i8`, which is required by `Vec<isize>: Index<_>`
    = help: the trait `SliceIndex<[isize]>` is implemented for `usize`
    = help: for that trait implementation, expected `usize`, found `i8`
    = note: required for `Vec<isize>` to implement `Index<i8>`
@@ -26,7 +26,7 @@ error[E0277]: the type `[isize]` cannot be indexed by `u32`
 LL |     v[3u32];
    |       ^^^^ slice indices are of type `usize` or ranges of `usize`
    |
-   = help: the trait `SliceIndex<[isize]>` is not implemented for `u32`
+   = help: the trait `SliceIndex<[isize]>` is not implemented for `u32`, which is required by `Vec<isize>: Index<_>`
    = help: the trait `SliceIndex<[isize]>` is implemented for `usize`
    = help: for that trait implementation, expected `usize`, found `u32`
    = note: required for `Vec<isize>` to implement `Index<u32>`
@@ -37,7 +37,7 @@ error[E0277]: the type `[isize]` cannot be indexed by `i32`
 LL |     v[3i32];
    |       ^^^^ slice indices are of type `usize` or ranges of `usize`
    |
-   = help: the trait `SliceIndex<[isize]>` is not implemented for `i32`
+   = help: the trait `SliceIndex<[isize]>` is not implemented for `i32`, which is required by `Vec<isize>: Index<_>`
    = help: the trait `SliceIndex<[isize]>` is implemented for `usize`
    = help: for that trait implementation, expected `usize`, found `i32`
    = note: required for `Vec<isize>` to implement `Index<i32>`
@@ -48,7 +48,7 @@ error[E0277]: the type `[u8]` cannot be indexed by `u8`
 LL |     s.as_bytes()[3u8];
    |                  ^^^ slice indices are of type `usize` or ranges of `usize`
    |
-   = help: the trait `SliceIndex<[u8]>` is not implemented for `u8`
+   = help: the trait `SliceIndex<[u8]>` is not implemented for `u8`, which is required by `[u8]: Index<_>`
    = help: the trait `SliceIndex<[u8]>` is implemented for `usize`
    = help: for that trait implementation, expected `usize`, found `u8`
    = note: required for `[u8]` to implement `Index<u8>`
@@ -59,7 +59,7 @@ error[E0277]: the type `[u8]` cannot be indexed by `i8`
 LL |     s.as_bytes()[3i8];
    |                  ^^^ slice indices are of type `usize` or ranges of `usize`
    |
-   = help: the trait `SliceIndex<[u8]>` is not implemented for `i8`
+   = help: the trait `SliceIndex<[u8]>` is not implemented for `i8`, which is required by `[u8]: Index<_>`
    = help: the trait `SliceIndex<[u8]>` is implemented for `usize`
    = help: for that trait implementation, expected `usize`, found `i8`
    = note: required for `[u8]` to implement `Index<i8>`
@@ -70,7 +70,7 @@ error[E0277]: the type `[u8]` cannot be indexed by `u32`
 LL |     s.as_bytes()[3u32];
    |                  ^^^^ slice indices are of type `usize` or ranges of `usize`
    |
-   = help: the trait `SliceIndex<[u8]>` is not implemented for `u32`
+   = help: the trait `SliceIndex<[u8]>` is not implemented for `u32`, which is required by `[u8]: Index<_>`
    = help: the trait `SliceIndex<[u8]>` is implemented for `usize`
    = help: for that trait implementation, expected `usize`, found `u32`
    = note: required for `[u8]` to implement `Index<u32>`
@@ -81,7 +81,7 @@ error[E0277]: the type `[u8]` cannot be indexed by `i32`
 LL |     s.as_bytes()[3i32];
    |                  ^^^^ slice indices are of type `usize` or ranges of `usize`
    |
-   = help: the trait `SliceIndex<[u8]>` is not implemented for `i32`
+   = help: the trait `SliceIndex<[u8]>` is not implemented for `i32`, which is required by `[u8]: Index<_>`
    = help: the trait `SliceIndex<[u8]>` is implemented for `usize`
    = help: for that trait implementation, expected `usize`, found `i32`
    = note: required for `[u8]` to implement `Index<i32>`
diff --git a/tests/ui/interior-mutability/interior-mutability.stderr b/tests/ui/interior-mutability/interior-mutability.stderr
index 36686565e2e..7b08a645405 100644
--- a/tests/ui/interior-mutability/interior-mutability.stderr
+++ b/tests/ui/interior-mutability/interior-mutability.stderr
@@ -6,7 +6,7 @@ LL |     catch_unwind(|| { x.set(23); });
    |     |
    |     required by a bound introduced by this call
    |
-   = help: within `Cell<i32>`, the trait `RefUnwindSafe` is not implemented for `UnsafeCell<i32>`
+   = help: within `Cell<i32>`, the trait `RefUnwindSafe` is not implemented for `UnsafeCell<i32>`, which is required by `{closure@$DIR/interior-mutability.rs:5:18: 5:20}: UnwindSafe`
 note: required because it appears within the type `Cell<i32>`
   --> $SRC_DIR/core/src/cell.rs:LL:COL
    = note: required for `&Cell<i32>` to implement `UnwindSafe`
diff --git a/tests/ui/issues/issue-21763.stderr b/tests/ui/issues/issue-21763.stderr
index 135b705eeef..aa4938a0c0b 100644
--- a/tests/ui/issues/issue-21763.stderr
+++ b/tests/ui/issues/issue-21763.stderr
@@ -4,7 +4,7 @@ error[E0277]: `Rc<()>` cannot be sent between threads safely
 LL |     foo::<HashMap<Rc<()>, Rc<()>>>();
    |           ^^^^^^^^^^^^^^^^^^^^^^^ `Rc<()>` cannot be sent between threads safely
    |
-   = help: within `(Rc<()>, Rc<()>)`, the trait `Send` is not implemented for `Rc<()>`
+   = help: within `(Rc<()>, Rc<()>)`, the trait `Send` is not implemented for `Rc<()>`, which is required by `HashMap<Rc<()>, Rc<()>>: Send`
    = note: required because it appears within the type `(Rc<()>, Rc<()>)`
    = note: required for `hashbrown::raw::RawTable<(Rc<()>, Rc<()>)>` to implement `Send`
 note: required because it appears within the type `hashbrown::map::HashMap<Rc<()>, Rc<()>, RandomState>`
diff --git a/tests/ui/issues/issue-22872.stderr b/tests/ui/issues/issue-22872.stderr
index 6ff710b1133..03e5393da48 100644
--- a/tests/ui/issues/issue-22872.stderr
+++ b/tests/ui/issues/issue-22872.stderr
@@ -4,7 +4,7 @@ error[E0277]: `<P as Process<'_>>::Item` is not an iterator
 LL |     let _: Box<dyn for<'b> Wrap<'b>> = Box::new(Wrapper(process));
    |                                        ^^^^^^^^^^^^^^^^^^^^^^^^^^ `<P as Process<'_>>::Item` is not an iterator
    |
-   = help: the trait `Iterator` is not implemented for `<P as Process<'_>>::Item`
+   = help: the trait `Iterator` is not implemented for `<P as Process<'_>>::Item`, which is required by `for<'b> Wrapper<P>: Wrap<'b>`
 note: required for `Wrapper<P>` to implement `for<'b> Wrap<'b>`
   --> $DIR/issue-22872.rs:7:13
    |
diff --git a/tests/ui/issues/issue-40827.stderr b/tests/ui/issues/issue-40827.stderr
index 7f5c578ae4f..44ae90cbc0f 100644
--- a/tests/ui/issues/issue-40827.stderr
+++ b/tests/ui/issues/issue-40827.stderr
@@ -6,7 +6,7 @@ LL |     f(Foo(Arc::new(Bar::B(None))));
    |     |
    |     required by a bound introduced by this call
    |
-   = help: within `Bar`, the trait `Sync` is not implemented for `Rc<Foo>`
+   = help: within `Bar`, the trait `Sync` is not implemented for `Rc<Foo>`, which is required by `Foo: Send`
 note: required because it appears within the type `Bar`
   --> $DIR/issue-40827.rs:6:6
    |
@@ -32,7 +32,7 @@ LL |     f(Foo(Arc::new(Bar::B(None))));
    |     |
    |     required by a bound introduced by this call
    |
-   = help: within `Bar`, the trait `Send` is not implemented for `Rc<Foo>`
+   = help: within `Bar`, the trait `Send` is not implemented for `Rc<Foo>`, which is required by `Foo: Send`
 note: required because it appears within the type `Bar`
   --> $DIR/issue-40827.rs:6:6
    |
diff --git a/tests/ui/issues/issue-7364.stderr b/tests/ui/issues/issue-7364.stderr
index 7371e2105de..15cb2d875c1 100644
--- a/tests/ui/issues/issue-7364.stderr
+++ b/tests/ui/issues/issue-7364.stderr
@@ -4,7 +4,7 @@ error[E0277]: `RefCell<isize>` cannot be shared between threads safely
 LL | static boxed: Box<RefCell<isize>> = Box::new(RefCell::new(0));
    |               ^^^^^^^^^^^^^^^^^^^ `RefCell<isize>` cannot be shared between threads safely
    |
-   = help: the trait `Sync` is not implemented for `RefCell<isize>`
+   = help: the trait `Sync` is not implemented for `RefCell<isize>`, which is required by `Box<RefCell<isize>>: Sync`
    = note: if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock` instead
    = note: required for `Unique<RefCell<isize>>` to implement `Sync`
 note: required because it appears within the type `Box<RefCell<isize>>`
diff --git a/tests/ui/iterators/float_iterator_hint.stderr b/tests/ui/iterators/float_iterator_hint.stderr
index c3cb00c3c68..29319b9400f 100644
--- a/tests/ui/iterators/float_iterator_hint.stderr
+++ b/tests/ui/iterators/float_iterator_hint.stderr
@@ -4,7 +4,7 @@ error[E0277]: `{float}` is not an iterator
 LL |     for i in 0.2 {
    |              ^^^ `{float}` is not an iterator
    |
-   = help: the trait `Iterator` is not implemented for `{float}`
+   = help: the trait `Iterator` is not implemented for `{float}`, which is required by `{float}: IntoIterator`
    = note: if you want to iterate between `start` until a value `end`, use the exclusive range syntax `start..end` or the inclusive range syntax `start..=end`
    = note: required for `{float}` to implement `IntoIterator`
 
diff --git a/tests/ui/iterators/integral.stderr b/tests/ui/iterators/integral.stderr
index c142fec8da0..74bbe28d6b7 100644
--- a/tests/ui/iterators/integral.stderr
+++ b/tests/ui/iterators/integral.stderr
@@ -4,7 +4,7 @@ error[E0277]: `{integer}` is not an iterator
 LL |     for _ in 42 {}
    |              ^^ `{integer}` is not an iterator
    |
-   = help: the trait `Iterator` is not implemented for `{integer}`
+   = help: the trait `Iterator` is not implemented for `{integer}`, which is required by `{integer}: IntoIterator`
    = note: if you want to iterate between `start` until a value `end`, use the exclusive range syntax `start..end` or the inclusive range syntax `start..=end`
    = note: required for `{integer}` to implement `IntoIterator`
 
@@ -14,7 +14,7 @@ error[E0277]: `u8` is not an iterator
 LL |     for _ in 42 as u8 {}
    |              ^^^^^^^^ `u8` is not an iterator
    |
-   = help: the trait `Iterator` is not implemented for `u8`
+   = help: the trait `Iterator` is not implemented for `u8`, which is required by `u8: IntoIterator`
    = note: if you want to iterate between `start` until a value `end`, use the exclusive range syntax `start..end` or the inclusive range syntax `start..=end`
    = note: required for `u8` to implement `IntoIterator`
 
@@ -24,7 +24,7 @@ error[E0277]: `i8` is not an iterator
 LL |     for _ in 42 as i8 {}
    |              ^^^^^^^^ `i8` is not an iterator
    |
-   = help: the trait `Iterator` is not implemented for `i8`
+   = help: the trait `Iterator` is not implemented for `i8`, which is required by `i8: IntoIterator`
    = note: if you want to iterate between `start` until a value `end`, use the exclusive range syntax `start..end` or the inclusive range syntax `start..=end`
    = note: required for `i8` to implement `IntoIterator`
 
@@ -34,7 +34,7 @@ error[E0277]: `u16` is not an iterator
 LL |     for _ in 42 as u16 {}
    |              ^^^^^^^^^ `u16` is not an iterator
    |
-   = help: the trait `Iterator` is not implemented for `u16`
+   = help: the trait `Iterator` is not implemented for `u16`, which is required by `u16: IntoIterator`
    = note: if you want to iterate between `start` until a value `end`, use the exclusive range syntax `start..end` or the inclusive range syntax `start..=end`
    = note: required for `u16` to implement `IntoIterator`
 
@@ -44,7 +44,7 @@ error[E0277]: `i16` is not an iterator
 LL |     for _ in 42 as i16 {}
    |              ^^^^^^^^^ `i16` is not an iterator
    |
-   = help: the trait `Iterator` is not implemented for `i16`
+   = help: the trait `Iterator` is not implemented for `i16`, which is required by `i16: IntoIterator`
    = note: if you want to iterate between `start` until a value `end`, use the exclusive range syntax `start..end` or the inclusive range syntax `start..=end`
    = note: required for `i16` to implement `IntoIterator`
 
@@ -54,7 +54,7 @@ error[E0277]: `u32` is not an iterator
 LL |     for _ in 42 as u32 {}
    |              ^^^^^^^^^ `u32` is not an iterator
    |
-   = help: the trait `Iterator` is not implemented for `u32`
+   = help: the trait `Iterator` is not implemented for `u32`, which is required by `u32: IntoIterator`
    = note: if you want to iterate between `start` until a value `end`, use the exclusive range syntax `start..end` or the inclusive range syntax `start..=end`
    = note: required for `u32` to implement `IntoIterator`
 
@@ -64,7 +64,7 @@ error[E0277]: `i32` is not an iterator
 LL |     for _ in 42 as i32 {}
    |              ^^^^^^^^^ `i32` is not an iterator
    |
-   = help: the trait `Iterator` is not implemented for `i32`
+   = help: the trait `Iterator` is not implemented for `i32`, which is required by `i32: IntoIterator`
    = note: if you want to iterate between `start` until a value `end`, use the exclusive range syntax `start..end` or the inclusive range syntax `start..=end`
    = note: required for `i32` to implement `IntoIterator`
 
@@ -74,7 +74,7 @@ error[E0277]: `u64` is not an iterator
 LL |     for _ in 42 as u64 {}
    |              ^^^^^^^^^ `u64` is not an iterator
    |
-   = help: the trait `Iterator` is not implemented for `u64`
+   = help: the trait `Iterator` is not implemented for `u64`, which is required by `u64: IntoIterator`
    = note: if you want to iterate between `start` until a value `end`, use the exclusive range syntax `start..end` or the inclusive range syntax `start..=end`
    = note: required for `u64` to implement `IntoIterator`
 
@@ -84,7 +84,7 @@ error[E0277]: `i64` is not an iterator
 LL |     for _ in 42 as i64 {}
    |              ^^^^^^^^^ `i64` is not an iterator
    |
-   = help: the trait `Iterator` is not implemented for `i64`
+   = help: the trait `Iterator` is not implemented for `i64`, which is required by `i64: IntoIterator`
    = note: if you want to iterate between `start` until a value `end`, use the exclusive range syntax `start..end` or the inclusive range syntax `start..=end`
    = note: required for `i64` to implement `IntoIterator`
 
@@ -94,7 +94,7 @@ error[E0277]: `usize` is not an iterator
 LL |     for _ in 42 as usize {}
    |              ^^^^^^^^^^^ `usize` is not an iterator
    |
-   = help: the trait `Iterator` is not implemented for `usize`
+   = help: the trait `Iterator` is not implemented for `usize`, which is required by `usize: IntoIterator`
    = note: if you want to iterate between `start` until a value `end`, use the exclusive range syntax `start..end` or the inclusive range syntax `start..=end`
    = note: required for `usize` to implement `IntoIterator`
 
@@ -104,7 +104,7 @@ error[E0277]: `isize` is not an iterator
 LL |     for _ in 42 as isize {}
    |              ^^^^^^^^^^^ `isize` is not an iterator
    |
-   = help: the trait `Iterator` is not implemented for `isize`
+   = help: the trait `Iterator` is not implemented for `isize`, which is required by `isize: IntoIterator`
    = note: if you want to iterate between `start` until a value `end`, use the exclusive range syntax `start..end` or the inclusive range syntax `start..=end`
    = note: required for `isize` to implement `IntoIterator`
 
@@ -114,7 +114,7 @@ error[E0277]: `{float}` is not an iterator
 LL |     for _ in 42.0 {}
    |              ^^^^ `{float}` is not an iterator
    |
-   = help: the trait `Iterator` is not implemented for `{float}`
+   = help: the trait `Iterator` is not implemented for `{float}`, which is required by `{float}: IntoIterator`
    = note: if you want to iterate between `start` until a value `end`, use the exclusive range syntax `start..end` or the inclusive range syntax `start..=end`
    = note: required for `{float}` to implement `IntoIterator`
 
diff --git a/tests/ui/iterators/issue-28098.stderr b/tests/ui/iterators/issue-28098.stderr
index a724f03ad4a..3cb1b2f7270 100644
--- a/tests/ui/iterators/issue-28098.stderr
+++ b/tests/ui/iterators/issue-28098.stderr
@@ -14,7 +14,7 @@ error[E0277]: `bool` is not an iterator
 LL |     for _ in false {}
    |              ^^^^^ `bool` is not an iterator
    |
-   = help: the trait `Iterator` is not implemented for `bool`
+   = help: the trait `Iterator` is not implemented for `bool`, which is required by `bool: IntoIterator`
    = note: required for `bool` to implement `IntoIterator`
 
 error[E0277]: `()` is not an iterator
@@ -61,7 +61,7 @@ error[E0277]: `bool` is not an iterator
 LL |     for _ in false {}
    |              ^^^^^ `bool` is not an iterator
    |
-   = help: the trait `Iterator` is not implemented for `bool`
+   = help: the trait `Iterator` is not implemented for `bool`, which is required by `bool: IntoIterator`
    = note: required for `bool` to implement `IntoIterator`
 
 error[E0277]: `()` is not an iterator
diff --git a/tests/ui/iterators/ranges.stderr b/tests/ui/iterators/ranges.stderr
index b9fbcd5304b..a5d43ecbb63 100644
--- a/tests/ui/iterators/ranges.stderr
+++ b/tests/ui/iterators/ranges.stderr
@@ -4,7 +4,7 @@ error[E0277]: `RangeTo<{integer}>` is not an iterator
 LL |     for _ in ..10 {}
    |              ^^^^ if you meant to iterate until a value, add a starting value
    |
-   = help: the trait `Iterator` is not implemented for `RangeTo<{integer}>`
+   = help: the trait `Iterator` is not implemented for `RangeTo<{integer}>`, which is required by `RangeTo<{integer}>: IntoIterator`
    = note: `..end` is a `RangeTo`, which cannot be iterated on; you might have meant to have a bounded `Range`: `0..end`
    = note: required for `RangeTo<{integer}>` to implement `IntoIterator`
 
@@ -14,7 +14,7 @@ error[E0277]: `RangeToInclusive<{integer}>` is not an iterator
 LL |     for _ in ..=10 {}
    |              ^^^^^ if you meant to iterate until a value (including it), add a starting value
    |
-   = help: the trait `Iterator` is not implemented for `RangeToInclusive<{integer}>`
+   = help: the trait `Iterator` is not implemented for `RangeToInclusive<{integer}>`, which is required by `RangeToInclusive<{integer}>: IntoIterator`
    = note: `..=end` is a `RangeToInclusive`, which cannot be iterated on; you might have meant to have a bounded `RangeInclusive`: `0..=end`
    = note: required for `RangeToInclusive<{integer}>` to implement `IntoIterator`
 
diff --git a/tests/ui/iterators/string.stderr b/tests/ui/iterators/string.stderr
index ddfe0169b84..29f560677c0 100644
--- a/tests/ui/iterators/string.stderr
+++ b/tests/ui/iterators/string.stderr
@@ -4,7 +4,7 @@ error[E0277]: `String` is not an iterator
 LL |     for _ in "".to_owned() {}
    |              ^^^^^^^^^^^^^ `String` is not an iterator; try calling `.chars()` or `.bytes()`
    |
-   = help: the trait `Iterator` is not implemented for `String`
+   = help: the trait `Iterator` is not implemented for `String`, which is required by `String: IntoIterator`
    = note: required for `String` to implement `IntoIterator`
 
 error[E0277]: `&str` is not an iterator
@@ -13,7 +13,7 @@ error[E0277]: `&str` is not an iterator
 LL |     for _ in "" {}
    |              ^^ `&str` is not an iterator; try calling `.chars()` or `.bytes()`
    |
-   = help: the trait `Iterator` is not implemented for `&str`
+   = help: the trait `Iterator` is not implemented for `&str`, which is required by `&str: IntoIterator`
    = note: required for `&str` to implement `IntoIterator`
 
 error: aborting due to 2 previous errors
diff --git a/tests/ui/kindck/kindck-impl-type-params-2.stderr b/tests/ui/kindck/kindck-impl-type-params-2.stderr
index a51232090ad..46c0bda9535 100644
--- a/tests/ui/kindck/kindck-impl-type-params-2.stderr
+++ b/tests/ui/kindck/kindck-impl-type-params-2.stderr
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `Box<{integer}>: Copy` is not satisfied
   --> $DIR/kindck-impl-type-params-2.rs:13:16
    |
 LL |     take_param(&x);
-   |     ---------- ^^ the trait `Copy` is not implemented for `Box<{integer}>`
+   |     ---------- ^^ the trait `Copy` is not implemented for `Box<{integer}>`, which is required by `Box<{integer}>: Foo`
    |     |
    |     required by a bound introduced by this call
    |
diff --git a/tests/ui/kindck/kindck-impl-type-params.stderr b/tests/ui/kindck/kindck-impl-type-params.stderr
index 53c1940491f..fe03ac422d2 100644
--- a/tests/ui/kindck/kindck-impl-type-params.stderr
+++ b/tests/ui/kindck/kindck-impl-type-params.stderr
@@ -21,7 +21,7 @@ error[E0277]: the trait bound `T: Copy` is not satisfied
   --> $DIR/kindck-impl-type-params.rs:16:13
    |
 LL |     let a = &t as &dyn Gettable<T>;
-   |             ^^ the trait `Copy` is not implemented for `T`
+   |             ^^ the trait `Copy` is not implemented for `T`, which is required by `S<T>: Gettable<T>`
    |
 note: required for `S<T>` to implement `Gettable<T>`
   --> $DIR/kindck-impl-type-params.rs:12:32
@@ -59,7 +59,7 @@ error[E0277]: the trait bound `T: Copy` is not satisfied
   --> $DIR/kindck-impl-type-params.rs:23:31
    |
 LL |     let a: &dyn Gettable<T> = &t;
-   |                               ^^ the trait `Copy` is not implemented for `T`
+   |                               ^^ the trait `Copy` is not implemented for `T`, which is required by `S<T>: Gettable<T>`
    |
 note: required for `S<T>` to implement `Gettable<T>`
   --> $DIR/kindck-impl-type-params.rs:12:32
@@ -78,7 +78,7 @@ error[E0277]: the trait bound `String: Copy` is not satisfied
   --> $DIR/kindck-impl-type-params.rs:35:13
    |
 LL |     let a = t as Box<dyn Gettable<String>>;
-   |             ^ the trait `Copy` is not implemented for `String`
+   |             ^ the trait `Copy` is not implemented for `String`, which is required by `S<String>: Gettable<String>`
    |
    = help: the trait `Gettable<T>` is implemented for `S<T>`
 note: required for `S<String>` to implement `Gettable<String>`
@@ -94,7 +94,7 @@ error[E0277]: the trait bound `Foo: Copy` is not satisfied
   --> $DIR/kindck-impl-type-params.rs:43:37
    |
 LL |     let a: Box<dyn Gettable<Foo>> = t;
-   |                                     ^ the trait `Copy` is not implemented for `Foo`
+   |                                     ^ the trait `Copy` is not implemented for `Foo`, which is required by `S<Foo>: Gettable<Foo>`
    |
    = help: the trait `Gettable<T>` is implemented for `S<T>`
 note: required for `S<Foo>` to implement `Gettable<Foo>`
diff --git a/tests/ui/kindck/kindck-inherited-copy-bound.curr.stderr b/tests/ui/kindck/kindck-inherited-copy-bound.curr.stderr
index 29495176556..a85815d8cc4 100644
--- a/tests/ui/kindck/kindck-inherited-copy-bound.curr.stderr
+++ b/tests/ui/kindck/kindck-inherited-copy-bound.curr.stderr
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `Box<{integer}>: Copy` is not satisfied
   --> $DIR/kindck-inherited-copy-bound.rs:21:16
    |
 LL |     take_param(&x);
-   |     ---------- ^^ the trait `Copy` is not implemented for `Box<{integer}>`
+   |     ---------- ^^ the trait `Copy` is not implemented for `Box<{integer}>`, which is required by `Box<{integer}>: Foo`
    |     |
    |     required by a bound introduced by this call
    |
diff --git a/tests/ui/kindck/kindck-inherited-copy-bound.object_safe_for_dispatch.stderr b/tests/ui/kindck/kindck-inherited-copy-bound.object_safe_for_dispatch.stderr
index 3e164ebf514..687660fe7ee 100644
--- a/tests/ui/kindck/kindck-inherited-copy-bound.object_safe_for_dispatch.stderr
+++ b/tests/ui/kindck/kindck-inherited-copy-bound.object_safe_for_dispatch.stderr
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `Box<{integer}>: Copy` is not satisfied
   --> $DIR/kindck-inherited-copy-bound.rs:21:16
    |
 LL |     take_param(&x);
-   |     ---------- ^^ the trait `Copy` is not implemented for `Box<{integer}>`
+   |     ---------- ^^ the trait `Copy` is not implemented for `Box<{integer}>`, which is required by `Box<{integer}>: Foo`
    |     |
    |     required by a bound introduced by this call
    |
diff --git a/tests/ui/kindck/kindck-nonsendable-1.stderr b/tests/ui/kindck/kindck-nonsendable-1.stderr
index 8bb784d1d49..8cc931bc48e 100644
--- a/tests/ui/kindck/kindck-nonsendable-1.stderr
+++ b/tests/ui/kindck/kindck-nonsendable-1.stderr
@@ -8,7 +8,7 @@ LL |     bar(move|| foo(x));
    |     |   within this `{closure@$DIR/kindck-nonsendable-1.rs:9:9: 9:15}`
    |     required by a bound introduced by this call
    |
-   = help: within `{closure@$DIR/kindck-nonsendable-1.rs:9:9: 9:15}`, the trait `Send` is not implemented for `Rc<usize>`
+   = help: within `{closure@$DIR/kindck-nonsendable-1.rs:9:9: 9:15}`, the trait `Send` is not implemented for `Rc<usize>`, which is required by `{closure@$DIR/kindck-nonsendable-1.rs:9:9: 9:15}: Send`
 note: required because it's used within this closure
   --> $DIR/kindck-nonsendable-1.rs:9:9
    |
diff --git a/tests/ui/kindck/kindck-send-object.stderr b/tests/ui/kindck/kindck-send-object.stderr
index 284d5dcec31..0fc9cb14c7d 100644
--- a/tests/ui/kindck/kindck-send-object.stderr
+++ b/tests/ui/kindck/kindck-send-object.stderr
@@ -4,7 +4,7 @@ error[E0277]: `(dyn Dummy + 'static)` cannot be shared between threads safely
 LL |     assert_send::<&'static (dyn Dummy + 'static)>();
    |                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `(dyn Dummy + 'static)` cannot be shared between threads safely
    |
-   = help: the trait `Sync` is not implemented for `(dyn Dummy + 'static)`
+   = help: the trait `Sync` is not implemented for `(dyn Dummy + 'static)`, which is required by `&'static (dyn Dummy + 'static): Send`
    = note: required for `&'static (dyn Dummy + 'static)` to implement `Send`
 note: required by a bound in `assert_send`
   --> $DIR/kindck-send-object.rs:5:18
@@ -18,7 +18,7 @@ error[E0277]: `dyn Dummy` cannot be sent between threads safely
 LL |     assert_send::<Box<dyn Dummy>>();
    |                   ^^^^^^^^^^^^^^ `dyn Dummy` cannot be sent between threads safely
    |
-   = help: the trait `Send` is not implemented for `dyn Dummy`
+   = help: the trait `Send` is not implemented for `dyn Dummy`, which is required by `Box<dyn Dummy>: Send`
    = note: required for `Unique<dyn Dummy>` to implement `Send`
 note: required because it appears within the type `Box<dyn Dummy>`
   --> $SRC_DIR/alloc/src/boxed.rs:LL:COL
diff --git a/tests/ui/kindck/kindck-send-object1.stderr b/tests/ui/kindck/kindck-send-object1.stderr
index c0d516e3f62..771c54dce0d 100644
--- a/tests/ui/kindck/kindck-send-object1.stderr
+++ b/tests/ui/kindck/kindck-send-object1.stderr
@@ -4,7 +4,7 @@ error[E0277]: `(dyn Dummy + 'a)` cannot be shared between threads safely
 LL |     assert_send::<&'a dyn Dummy>();
    |                   ^^^^^^^^^^^^^ `(dyn Dummy + 'a)` cannot be shared between threads safely
    |
-   = help: the trait `Sync` is not implemented for `(dyn Dummy + 'a)`
+   = help: the trait `Sync` is not implemented for `(dyn Dummy + 'a)`, which is required by `&'a (dyn Dummy + 'a): Send`
    = note: required for `&'a (dyn Dummy + 'a)` to implement `Send`
 note: required by a bound in `assert_send`
   --> $DIR/kindck-send-object1.rs:5:18
@@ -18,7 +18,7 @@ error[E0277]: `(dyn Dummy + 'a)` cannot be sent between threads safely
 LL |     assert_send::<Box<dyn Dummy + 'a>>();
    |                   ^^^^^^^^^^^^^^^^^^^ `(dyn Dummy + 'a)` cannot be sent between threads safely
    |
-   = help: the trait `Send` is not implemented for `(dyn Dummy + 'a)`
+   = help: the trait `Send` is not implemented for `(dyn Dummy + 'a)`, which is required by `Box<(dyn Dummy + 'a)>: Send`
    = note: required for `Unique<(dyn Dummy + 'a)>` to implement `Send`
 note: required because it appears within the type `Box<(dyn Dummy + 'a)>`
   --> $SRC_DIR/alloc/src/boxed.rs:LL:COL
diff --git a/tests/ui/kindck/kindck-send-object2.stderr b/tests/ui/kindck/kindck-send-object2.stderr
index 6b8df60227f..758a517e128 100644
--- a/tests/ui/kindck/kindck-send-object2.stderr
+++ b/tests/ui/kindck/kindck-send-object2.stderr
@@ -4,7 +4,7 @@ error[E0277]: `(dyn Dummy + 'static)` cannot be shared between threads safely
 LL |     assert_send::<&'static dyn Dummy>();
    |                   ^^^^^^^^^^^^^^^^^^ `(dyn Dummy + 'static)` cannot be shared between threads safely
    |
-   = help: the trait `Sync` is not implemented for `(dyn Dummy + 'static)`
+   = help: the trait `Sync` is not implemented for `(dyn Dummy + 'static)`, which is required by `&'static (dyn Dummy + 'static): Send`
    = note: required for `&'static (dyn Dummy + 'static)` to implement `Send`
 note: required by a bound in `assert_send`
   --> $DIR/kindck-send-object2.rs:3:18
@@ -18,7 +18,7 @@ error[E0277]: `dyn Dummy` cannot be sent between threads safely
 LL |     assert_send::<Box<dyn Dummy>>();
    |                   ^^^^^^^^^^^^^^ `dyn Dummy` cannot be sent between threads safely
    |
-   = help: the trait `Send` is not implemented for `dyn Dummy`
+   = help: the trait `Send` is not implemented for `dyn Dummy`, which is required by `Box<dyn Dummy>: Send`
    = note: required for `Unique<dyn Dummy>` to implement `Send`
 note: required because it appears within the type `Box<dyn Dummy>`
   --> $SRC_DIR/alloc/src/boxed.rs:LL:COL
diff --git a/tests/ui/kindck/kindck-send-owned.stderr b/tests/ui/kindck/kindck-send-owned.stderr
index 860a9391bbb..4bc0212089b 100644
--- a/tests/ui/kindck/kindck-send-owned.stderr
+++ b/tests/ui/kindck/kindck-send-owned.stderr
@@ -4,7 +4,7 @@ error[E0277]: `*mut u8` cannot be sent between threads safely
 LL |     assert_send::<Box<*mut u8>>();
    |                   ^^^^^^^^^^^^ `*mut u8` cannot be sent between threads safely
    |
-   = help: the trait `Send` is not implemented for `*mut u8`
+   = help: the trait `Send` is not implemented for `*mut u8`, which is required by `Box<*mut u8>: Send`
    = note: required for `Unique<*mut u8>` to implement `Send`
 note: required because it appears within the type `Box<*mut u8>`
   --> $SRC_DIR/alloc/src/boxed.rs:LL:COL
diff --git a/tests/ui/lang-items/duplicate.rs b/tests/ui/lang-items/duplicate.rs
new file mode 100644
index 00000000000..f88d2354414
--- /dev/null
+++ b/tests/ui/lang-items/duplicate.rs
@@ -0,0 +1,10 @@
+// normalize-stderr-test "loaded from .*libcore-.*.rlib" -> "loaded from SYSROOT/libcore-*.rlib"
+#![feature(lang_items)]
+
+#[lang = "sized"]
+trait Sized {}
+//~^ ERROR: duplicate lang item
+
+#[lang = "tuple_trait"]
+pub trait Tuple {}
+// no error
diff --git a/tests/ui/lang-items/duplicate.stderr b/tests/ui/lang-items/duplicate.stderr
new file mode 100644
index 00000000000..aaa8f5e605a
--- /dev/null
+++ b/tests/ui/lang-items/duplicate.stderr
@@ -0,0 +1,13 @@
+error[E0152]: found duplicate lang item `sized`
+  --> $DIR/duplicate.rs:5:1
+   |
+LL | trait Sized {}
+   | ^^^^^^^^^^^^^^
+   |
+   = note: the lang item is first defined in crate `core` (which `std` depends on)
+   = note: first definition in `core` loaded from SYSROOT/libcore-*.rlib
+   = note: second definition in the local crate (`duplicate`)
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0152`.
diff --git a/tests/ui/modules/issue-107649.stderr b/tests/ui/modules/issue-107649.stderr
index 0d203c1aacb..d5405c6576a 100644
--- a/tests/ui/modules/issue-107649.stderr
+++ b/tests/ui/modules/issue-107649.stderr
@@ -4,7 +4,7 @@ error[E0277]: `Dummy` doesn't implement `Debug`
 105 |     dbg!(lib::Dummy);
     |     ^^^^^^^^^^^^^^^^ `Dummy` cannot be formatted using `{:?}`
     |
-    = help: the trait `Debug` is not implemented for `Dummy`
+    = help: the trait `Debug` is not implemented for `Dummy`, which is required by `&Dummy: Debug`
     = note: add `#[derive(Debug)]` to `Dummy` or manually `impl Debug for Dummy`
     = note: this error originates in the macro `$crate::format_args_nl` which comes from the expansion of the macro `dbg` (in Nightly builds, run with -Z macro-backtrace for more info)
 help: consider annotating `Dummy` with `#[derive(Debug)]`
diff --git a/tests/ui/mut/mutable-enum-indirect.stderr b/tests/ui/mut/mutable-enum-indirect.stderr
index 0b7783b3318..d7af327df5a 100644
--- a/tests/ui/mut/mutable-enum-indirect.stderr
+++ b/tests/ui/mut/mutable-enum-indirect.stderr
@@ -6,7 +6,7 @@ LL |     bar(&x);
    |     |
    |     required by a bound introduced by this call
    |
-   = help: within `&Foo`, the trait `Sync` is not implemented for `NoSync`
+   = help: within `&Foo`, the trait `Sync` is not implemented for `NoSync`, which is required by `&Foo: Sync`
 note: required because it appears within the type `Foo`
   --> $DIR/mutable-enum-indirect.rs:11:6
    |
diff --git a/tests/ui/no-send-res-ports.stderr b/tests/ui/no-send-res-ports.stderr
index 9c30261e5cb..c71d8ecba37 100644
--- a/tests/ui/no-send-res-ports.stderr
+++ b/tests/ui/no-send-res-ports.stderr
@@ -13,7 +13,7 @@ LL | |         println!("{:?}", y);
 LL | |     });
    | |_____^ `Rc<()>` cannot be sent between threads safely
    |
-   = help: within `{closure@$DIR/no-send-res-ports.rs:25:19: 25:25}`, the trait `Send` is not implemented for `Rc<()>`
+   = help: within `{closure@$DIR/no-send-res-ports.rs:25:19: 25:25}`, the trait `Send` is not implemented for `Rc<()>`, which is required by `{closure@$DIR/no-send-res-ports.rs:25:19: 25:25}: Send`
 note: required because it appears within the type `Port<()>`
   --> $DIR/no-send-res-ports.rs:5:8
    |
diff --git a/tests/ui/no_send-enum.stderr b/tests/ui/no_send-enum.stderr
index 3b66c7db545..e24f79c7dd6 100644
--- a/tests/ui/no_send-enum.stderr
+++ b/tests/ui/no_send-enum.stderr
@@ -6,7 +6,7 @@ LL |     bar(x);
    |     |
    |     required by a bound introduced by this call
    |
-   = help: within `Foo`, the trait `Send` is not implemented for `NoSend`
+   = help: within `Foo`, the trait `Send` is not implemented for `NoSend`, which is required by `Foo: Send`
 note: required because it appears within the type `Foo`
   --> $DIR/no_send-enum.rs:8:6
    |
diff --git a/tests/ui/no_share-enum.stderr b/tests/ui/no_share-enum.stderr
index 89939216d5b..5b6c8bf0b4f 100644
--- a/tests/ui/no_share-enum.stderr
+++ b/tests/ui/no_share-enum.stderr
@@ -6,7 +6,7 @@ LL |     bar(x);
    |     |
    |     required by a bound introduced by this call
    |
-   = help: within `Foo`, the trait `Sync` is not implemented for `NoSync`
+   = help: within `Foo`, the trait `Sync` is not implemented for `NoSync`, which is required by `Foo: Sync`
 note: required because it appears within the type `Foo`
   --> $DIR/no_share-enum.rs:8:6
    |
diff --git a/tests/ui/not-clone-closure.stderr b/tests/ui/not-clone-closure.stderr
index 783c165eeb2..9b557b15582 100644
--- a/tests/ui/not-clone-closure.stderr
+++ b/tests/ui/not-clone-closure.stderr
@@ -5,7 +5,7 @@ LL |     let hello = move || {
    |                 ------- within this `{closure@$DIR/not-clone-closure.rs:7:17: 7:24}`
 ...
 LL |     let hello = hello.clone();
-   |                       ^^^^^ within `{closure@$DIR/not-clone-closure.rs:7:17: 7:24}`, the trait `Clone` is not implemented for `S`
+   |                       ^^^^^ within `{closure@$DIR/not-clone-closure.rs:7:17: 7:24}`, the trait `Clone` is not implemented for `S`, which is required by `{closure@$DIR/not-clone-closure.rs:7:17: 7:24}: Clone`
    |
 note: required because it's used within this closure
   --> $DIR/not-clone-closure.rs:7:17
diff --git a/tests/ui/not-panic/not-panic-safe-2.stderr b/tests/ui/not-panic/not-panic-safe-2.stderr
index 0c399f15a25..8c4cf9c98ed 100644
--- a/tests/ui/not-panic/not-panic-safe-2.stderr
+++ b/tests/ui/not-panic/not-panic-safe-2.stderr
@@ -4,7 +4,7 @@ error[E0277]: the type `UnsafeCell<i32>` may contain interior mutability and a r
 LL |     assert::<Rc<RefCell<i32>>>();
    |              ^^^^^^^^^^^^^^^^ `UnsafeCell<i32>` may contain interior mutability and a reference may not be safely transferrable across a catch_unwind boundary
    |
-   = help: within `RefCell<i32>`, the trait `RefUnwindSafe` is not implemented for `UnsafeCell<i32>`
+   = help: within `RefCell<i32>`, the trait `RefUnwindSafe` is not implemented for `UnsafeCell<i32>`, which is required by `Rc<RefCell<i32>>: UnwindSafe`
 note: required because it appears within the type `RefCell<i32>`
   --> $SRC_DIR/core/src/cell.rs:LL:COL
    = note: required for `Rc<RefCell<i32>>` to implement `UnwindSafe`
@@ -20,7 +20,7 @@ error[E0277]: the type `UnsafeCell<isize>` may contain interior mutability and a
 LL |     assert::<Rc<RefCell<i32>>>();
    |              ^^^^^^^^^^^^^^^^ `UnsafeCell<isize>` may contain interior mutability and a reference may not be safely transferrable across a catch_unwind boundary
    |
-   = help: within `RefCell<i32>`, the trait `RefUnwindSafe` is not implemented for `UnsafeCell<isize>`
+   = help: within `RefCell<i32>`, the trait `RefUnwindSafe` is not implemented for `UnsafeCell<isize>`, which is required by `Rc<RefCell<i32>>: UnwindSafe`
 note: required because it appears within the type `Cell<isize>`
   --> $SRC_DIR/core/src/cell.rs:LL:COL
 note: required because it appears within the type `RefCell<i32>`
diff --git a/tests/ui/not-panic/not-panic-safe-3.stderr b/tests/ui/not-panic/not-panic-safe-3.stderr
index 53028d6a337..2373ada63f6 100644
--- a/tests/ui/not-panic/not-panic-safe-3.stderr
+++ b/tests/ui/not-panic/not-panic-safe-3.stderr
@@ -4,7 +4,7 @@ error[E0277]: the type `UnsafeCell<i32>` may contain interior mutability and a r
 LL |     assert::<Arc<RefCell<i32>>>();
    |              ^^^^^^^^^^^^^^^^^ `UnsafeCell<i32>` may contain interior mutability and a reference may not be safely transferrable across a catch_unwind boundary
    |
-   = help: within `RefCell<i32>`, the trait `RefUnwindSafe` is not implemented for `UnsafeCell<i32>`
+   = help: within `RefCell<i32>`, the trait `RefUnwindSafe` is not implemented for `UnsafeCell<i32>`, which is required by `Arc<RefCell<i32>>: UnwindSafe`
 note: required because it appears within the type `RefCell<i32>`
   --> $SRC_DIR/core/src/cell.rs:LL:COL
    = note: required for `Arc<RefCell<i32>>` to implement `UnwindSafe`
@@ -20,7 +20,7 @@ error[E0277]: the type `UnsafeCell<isize>` may contain interior mutability and a
 LL |     assert::<Arc<RefCell<i32>>>();
    |              ^^^^^^^^^^^^^^^^^ `UnsafeCell<isize>` may contain interior mutability and a reference may not be safely transferrable across a catch_unwind boundary
    |
-   = help: within `RefCell<i32>`, the trait `RefUnwindSafe` is not implemented for `UnsafeCell<isize>`
+   = help: within `RefCell<i32>`, the trait `RefUnwindSafe` is not implemented for `UnsafeCell<isize>`, which is required by `Arc<RefCell<i32>>: UnwindSafe`
 note: required because it appears within the type `Cell<isize>`
   --> $SRC_DIR/core/src/cell.rs:LL:COL
 note: required because it appears within the type `RefCell<i32>`
diff --git a/tests/ui/not-panic/not-panic-safe-4.stderr b/tests/ui/not-panic/not-panic-safe-4.stderr
index b1361cfd87e..d77cac8f272 100644
--- a/tests/ui/not-panic/not-panic-safe-4.stderr
+++ b/tests/ui/not-panic/not-panic-safe-4.stderr
@@ -4,7 +4,7 @@ error[E0277]: the type `UnsafeCell<i32>` may contain interior mutability and a r
 LL |     assert::<&RefCell<i32>>();
    |              ^^^^^^^^^^^^^ `UnsafeCell<i32>` may contain interior mutability and a reference may not be safely transferrable across a catch_unwind boundary
    |
-   = help: within `RefCell<i32>`, the trait `RefUnwindSafe` is not implemented for `UnsafeCell<i32>`
+   = help: within `RefCell<i32>`, the trait `RefUnwindSafe` is not implemented for `UnsafeCell<i32>`, which is required by `&RefCell<i32>: UnwindSafe`
 note: required because it appears within the type `RefCell<i32>`
   --> $SRC_DIR/core/src/cell.rs:LL:COL
    = note: required for `&RefCell<i32>` to implement `UnwindSafe`
@@ -25,7 +25,7 @@ error[E0277]: the type `UnsafeCell<isize>` may contain interior mutability and a
 LL |     assert::<&RefCell<i32>>();
    |              ^^^^^^^^^^^^^ `UnsafeCell<isize>` may contain interior mutability and a reference may not be safely transferrable across a catch_unwind boundary
    |
-   = help: within `RefCell<i32>`, the trait `RefUnwindSafe` is not implemented for `UnsafeCell<isize>`
+   = help: within `RefCell<i32>`, the trait `RefUnwindSafe` is not implemented for `UnsafeCell<isize>`, which is required by `&RefCell<i32>: UnwindSafe`
 note: required because it appears within the type `Cell<isize>`
   --> $SRC_DIR/core/src/cell.rs:LL:COL
 note: required because it appears within the type `RefCell<i32>`
diff --git a/tests/ui/not-panic/not-panic-safe-5.stderr b/tests/ui/not-panic/not-panic-safe-5.stderr
index fbbd81d6d4c..0de9a2cc0cd 100644
--- a/tests/ui/not-panic/not-panic-safe-5.stderr
+++ b/tests/ui/not-panic/not-panic-safe-5.stderr
@@ -4,7 +4,7 @@ error[E0277]: the type `UnsafeCell<i32>` may contain interior mutability and a r
 LL |     assert::<*const UnsafeCell<i32>>();
    |              ^^^^^^^^^^^^^^^^^^^^^^ `UnsafeCell<i32>` may contain interior mutability and a reference may not be safely transferrable across a catch_unwind boundary
    |
-   = help: the trait `RefUnwindSafe` is not implemented for `UnsafeCell<i32>`
+   = help: the trait `RefUnwindSafe` is not implemented for `UnsafeCell<i32>`, which is required by `*const UnsafeCell<i32>: UnwindSafe`
    = note: required for `*const UnsafeCell<i32>` to implement `UnwindSafe`
 note: required by a bound in `assert`
   --> $DIR/not-panic-safe-5.rs:6:14
diff --git a/tests/ui/not-panic/not-panic-safe-6.stderr b/tests/ui/not-panic/not-panic-safe-6.stderr
index 47f28257409..7714a577f8a 100644
--- a/tests/ui/not-panic/not-panic-safe-6.stderr
+++ b/tests/ui/not-panic/not-panic-safe-6.stderr
@@ -4,7 +4,7 @@ error[E0277]: the type `UnsafeCell<i32>` may contain interior mutability and a r
 LL |     assert::<*mut RefCell<i32>>();
    |              ^^^^^^^^^^^^^^^^^ `UnsafeCell<i32>` may contain interior mutability and a reference may not be safely transferrable across a catch_unwind boundary
    |
-   = help: within `RefCell<i32>`, the trait `RefUnwindSafe` is not implemented for `UnsafeCell<i32>`
+   = help: within `RefCell<i32>`, the trait `RefUnwindSafe` is not implemented for `UnsafeCell<i32>`, which is required by `*mut RefCell<i32>: UnwindSafe`
 note: required because it appears within the type `RefCell<i32>`
   --> $SRC_DIR/core/src/cell.rs:LL:COL
    = note: required for `*mut RefCell<i32>` to implement `UnwindSafe`
@@ -20,7 +20,7 @@ error[E0277]: the type `UnsafeCell<isize>` may contain interior mutability and a
 LL |     assert::<*mut RefCell<i32>>();
    |              ^^^^^^^^^^^^^^^^^ `UnsafeCell<isize>` may contain interior mutability and a reference may not be safely transferrable across a catch_unwind boundary
    |
-   = help: within `RefCell<i32>`, the trait `RefUnwindSafe` is not implemented for `UnsafeCell<isize>`
+   = help: within `RefCell<i32>`, the trait `RefUnwindSafe` is not implemented for `UnsafeCell<isize>`, which is required by `*mut RefCell<i32>: UnwindSafe`
 note: required because it appears within the type `Cell<isize>`
   --> $SRC_DIR/core/src/cell.rs:LL:COL
 note: required because it appears within the type `RefCell<i32>`
diff --git a/tests/ui/offset-of/offset-of-dst-field.stderr b/tests/ui/offset-of/offset-of-dst-field.stderr
index 658678dc4ed..753ba809e7d 100644
--- a/tests/ui/offset-of/offset-of-dst-field.stderr
+++ b/tests/ui/offset-of/offset-of-dst-field.stderr
@@ -40,7 +40,7 @@ error[E0277]: the size for values of type `[u8]` cannot be known at compilation
 LL |     offset_of!(Delta<Alpha>, z);
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
    |
-   = help: within `Alpha`, the trait `Sized` is not implemented for `[u8]`
+   = help: within `Alpha`, the trait `Sized` is not implemented for `[u8]`, which is required by `Alpha: Sized`
 note: required because it appears within the type `Alpha`
   --> $DIR/offset-of-dst-field.rs:5:8
    |
diff --git a/tests/ui/on-unimplemented/slice-index.stderr b/tests/ui/on-unimplemented/slice-index.stderr
index 5e0117be529..c0314fa42d7 100644
--- a/tests/ui/on-unimplemented/slice-index.stderr
+++ b/tests/ui/on-unimplemented/slice-index.stderr
@@ -4,7 +4,7 @@ error[E0277]: the type `[i32]` cannot be indexed by `i32`
 LL |     x[1i32];
    |       ^^^^ slice indices are of type `usize` or ranges of `usize`
    |
-   = help: the trait `SliceIndex<[i32]>` is not implemented for `i32`
+   = help: the trait `SliceIndex<[i32]>` is not implemented for `i32`, which is required by `[i32]: Index<_>`
    = help: the trait `SliceIndex<[i32]>` is implemented for `usize`
    = help: for that trait implementation, expected `usize`, found `i32`
    = note: required for `[i32]` to implement `Index<i32>`
@@ -15,7 +15,7 @@ error[E0277]: the type `[i32]` cannot be indexed by `RangeTo<i32>`
 LL |     x[..1i32];
    |       ^^^^^^ slice indices are of type `usize` or ranges of `usize`
    |
-   = help: the trait `SliceIndex<[i32]>` is not implemented for `RangeTo<i32>`
+   = help: the trait `SliceIndex<[i32]>` is not implemented for `RangeTo<i32>`, which is required by `[i32]: Index<_>`
    = help: the following other types implement trait `SliceIndex<T>`:
              <RangeTo<usize> as SliceIndex<str>>
              <RangeTo<usize> as SliceIndex<[T]>>
diff --git a/tests/ui/parser/struct-literal-in-for.stderr b/tests/ui/parser/struct-literal-in-for.stderr
index 1c91eba68e3..d2ef2ad7b5a 100644
--- a/tests/ui/parser/struct-literal-in-for.stderr
+++ b/tests/ui/parser/struct-literal-in-for.stderr
@@ -23,7 +23,7 @@ LL | |         x: 3
 LL | |     }.hi() {
    | |__________^ `bool` is not an iterator
    |
-   = help: the trait `Iterator` is not implemented for `bool`
+   = help: the trait `Iterator` is not implemented for `bool`, which is required by `bool: IntoIterator`
    = note: required for `bool` to implement `IntoIterator`
 
 error: aborting due to 2 previous errors
diff --git a/tests/ui/range/range-1.stderr b/tests/ui/range/range-1.stderr
index 96c1ffb2f7e..569f700cf10 100644
--- a/tests/ui/range/range-1.stderr
+++ b/tests/ui/range/range-1.stderr
@@ -8,7 +8,7 @@ error[E0277]: the trait bound `bool: Step` is not satisfied
   --> $DIR/range-1.rs:9:14
    |
 LL |     for i in false..true {}
-   |              ^^^^^^^^^^^ the trait `Step` is not implemented for `bool`
+   |              ^^^^^^^^^^^ the trait `Step` is not implemented for `bool`, which is required by `std::ops::Range<bool>: IntoIterator`
    |
    = help: the following other types implement trait `Step`:
              char
diff --git a/tests/ui/recursion/recursive-requirements.stderr b/tests/ui/recursion/recursive-requirements.stderr
index bb63f7cd0dc..f5cbed0ce34 100644
--- a/tests/ui/recursion/recursive-requirements.stderr
+++ b/tests/ui/recursion/recursive-requirements.stderr
@@ -4,7 +4,7 @@ error[E0277]: `*const Bar` cannot be shared between threads safely
 LL |     let _: AssertSync<Foo> = unimplemented!();
    |            ^^^^^^^^^^^^^^^ `*const Bar` cannot be shared between threads safely
    |
-   = help: within `Foo`, the trait `Sync` is not implemented for `*const Bar`
+   = help: within `Foo`, the trait `Sync` is not implemented for `*const Bar`, which is required by `Foo: Sync`
 note: required because it appears within the type `Foo`
   --> $DIR/recursive-requirements.rs:5:12
    |
@@ -22,7 +22,7 @@ error[E0277]: `*const Foo` cannot be shared between threads safely
 LL |     let _: AssertSync<Foo> = unimplemented!();
    |            ^^^^^^^^^^^^^^^ `*const Foo` cannot be shared between threads safely
    |
-   = help: within `Foo`, the trait `Sync` is not implemented for `*const Foo`
+   = help: within `Foo`, the trait `Sync` is not implemented for `*const Foo`, which is required by `Foo: Sync`
 note: required because it appears within the type `Bar`
   --> $DIR/recursive-requirements.rs:10:12
    |
diff --git a/tests/ui/rfcs/rfc-1937-termination-trait/termination-trait-test-wrong-type.stderr b/tests/ui/rfcs/rfc-1937-termination-trait/termination-trait-test-wrong-type.stderr
index 0a703367d96..4d23922892e 100644
--- a/tests/ui/rfcs/rfc-1937-termination-trait/termination-trait-test-wrong-type.stderr
+++ b/tests/ui/rfcs/rfc-1937-termination-trait/termination-trait-test-wrong-type.stderr
@@ -4,7 +4,7 @@ error[E0277]: the trait bound `f32: Termination` is not satisfied
 LL | #[test]
    | ------- in this procedural macro expansion
 LL | fn can_parse_zero_as_f32() -> Result<f32, ParseFloatError> {
-   |                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Termination` is not implemented for `f32`
+   |                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Termination` is not implemented for `f32`, which is required by `Result<f32, ParseFloatError>: Termination`
    |
    = note: required for `Result<f32, ParseFloatError>` to implement `Termination`
 note: required by a bound in `assert_test_result`
diff --git a/tests/ui/rfcs/rfc-2361-dbg-macro/dbg-macro-requires-debug.stderr b/tests/ui/rfcs/rfc-2361-dbg-macro/dbg-macro-requires-debug.stderr
index 7ec018a95cc..eb6abbf8045 100644
--- a/tests/ui/rfcs/rfc-2361-dbg-macro/dbg-macro-requires-debug.stderr
+++ b/tests/ui/rfcs/rfc-2361-dbg-macro/dbg-macro-requires-debug.stderr
@@ -4,7 +4,7 @@ error[E0277]: `NotDebug` doesn't implement `Debug`
 LL |     let _: NotDebug = dbg!(NotDebug);
    |                       ^^^^^^^^^^^^^^ `NotDebug` cannot be formatted using `{:?}`
    |
-   = help: the trait `Debug` is not implemented for `NotDebug`
+   = help: the trait `Debug` is not implemented for `NotDebug`, which is required by `&NotDebug: Debug`
    = note: add `#[derive(Debug)]` to `NotDebug` or manually `impl Debug for NotDebug`
    = note: this error originates in the macro `$crate::format_args_nl` which comes from the expansion of the macro `dbg` (in Nightly builds, run with -Z macro-backtrace for more info)
 help: consider annotating `NotDebug` with `#[derive(Debug)]`
diff --git a/tests/ui/rfcs/rfc-2397-do-not-recommend/feature-gate-do_not_recommend.stderr b/tests/ui/rfcs/rfc-2397-do-not-recommend/feature-gate-do_not_recommend.stderr
index 6af1d4533b7..99d318a7933 100644
--- a/tests/ui/rfcs/rfc-2397-do-not-recommend/feature-gate-do_not_recommend.stderr
+++ b/tests/ui/rfcs/rfc-2397-do-not-recommend/feature-gate-do_not_recommend.stderr
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `u8: Foo` is not satisfied
   --> $DIR/feature-gate-do_not_recommend.rs:19:11
    |
 LL |     stuff(1u8);
-   |     ----- ^^^ the trait `Foo` is not implemented for `u8`
+   |     ----- ^^^ the trait `Foo` is not implemented for `u8`, which is required by `u8: Bar`
    |     |
    |     required by a bound introduced by this call
    |
diff --git a/tests/ui/specialization/min_specialization/issue-79224.stderr b/tests/ui/specialization/min_specialization/issue-79224.stderr
index 37ced4cf267..da19ed44ce6 100644
--- a/tests/ui/specialization/min_specialization/issue-79224.stderr
+++ b/tests/ui/specialization/min_specialization/issue-79224.stderr
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `B: Clone` is not satisfied
   --> $DIR/issue-79224.rs:18:29
    |
 LL | impl<B: ?Sized> Display for Cow<'_, B> {
-   |                             ^^^^^^^^^^ the trait `Clone` is not implemented for `B`
+   |                             ^^^^^^^^^^ the trait `Clone` is not implemented for `B`, which is required by `B: ToOwned`
    |
    = note: required for `B` to implement `ToOwned`
 help: consider further restricting this bound
@@ -14,7 +14,7 @@ error[E0277]: the trait bound `B: Clone` is not satisfied
   --> $DIR/issue-79224.rs:20:5
    |
 LL |     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Clone` is not implemented for `B`
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Clone` is not implemented for `B`, which is required by `B: ToOwned`
    |
    = note: required for `B` to implement `ToOwned`
 help: consider further restricting this bound
@@ -26,7 +26,7 @@ error[E0277]: the trait bound `B: Clone` is not satisfied
   --> $DIR/issue-79224.rs:20:13
    |
 LL |     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-   |             ^^^^ the trait `Clone` is not implemented for `B`
+   |             ^^^^ the trait `Clone` is not implemented for `B`, which is required by `B: ToOwned`
    |
    = note: required for `B` to implement `ToOwned`
 help: consider further restricting this bound
diff --git a/tests/ui/str/str-idx.stderr b/tests/ui/str/str-idx.stderr
index e8bbb8058fa..84806cbea0d 100644
--- a/tests/ui/str/str-idx.stderr
+++ b/tests/ui/str/str-idx.stderr
@@ -4,7 +4,7 @@ error[E0277]: the type `str` cannot be indexed by `{integer}`
 LL |     let _: u8 = s[4];
    |                   ^ string indices are ranges of `usize`
    |
-   = help: the trait `SliceIndex<str>` is not implemented for `{integer}`
+   = help: the trait `SliceIndex<str>` is not implemented for `{integer}`, which is required by `str: Index<_>`
    = note: you can use `.chars().nth()` or `.bytes().nth()`
            for more information, see chapter 8 in The Book: <https://doc.rust-lang.org/book/ch08-02-strings.html#indexing-into-strings>
    = help: the trait `SliceIndex<[_]>` is implemented for `usize`
@@ -49,7 +49,7 @@ error[E0277]: the type `str` cannot be indexed by `char`
 LL |     let _: u8 = s['c'];
    |                   ^^^ string indices are ranges of `usize`
    |
-   = help: the trait `SliceIndex<str>` is not implemented for `char`
+   = help: the trait `SliceIndex<str>` is not implemented for `char`, which is required by `str: Index<_>`
    = note: required for `str` to implement `Index<char>`
 
 error: aborting due to 4 previous errors
diff --git a/tests/ui/str/str-mut-idx.stderr b/tests/ui/str/str-mut-idx.stderr
index d41f5808752..17a75bf8c2a 100644
--- a/tests/ui/str/str-mut-idx.stderr
+++ b/tests/ui/str/str-mut-idx.stderr
@@ -30,7 +30,7 @@ error[E0277]: the type `str` cannot be indexed by `usize`
 LL |     s[1usize] = bot();
    |       ^^^^^^ string indices are ranges of `usize`
    |
-   = help: the trait `SliceIndex<str>` is not implemented for `usize`
+   = help: the trait `SliceIndex<str>` is not implemented for `usize`, which is required by `str: Index<_>`
    = help: the trait `SliceIndex<[_]>` is implemented for `usize`
    = help: for that trait implementation, expected `[_]`, found `str`
    = note: required for `str` to implement `Index<usize>`
@@ -73,7 +73,7 @@ error[E0277]: the type `str` cannot be indexed by `char`
 LL |     s['c'];
    |       ^^^ string indices are ranges of `usize`
    |
-   = help: the trait `SliceIndex<str>` is not implemented for `char`
+   = help: the trait `SliceIndex<str>` is not implemented for `char`, which is required by `str: Index<_>`
    = note: required for `str` to implement `Index<char>`
 
 error: aborting due to 6 previous errors
diff --git a/tests/ui/suggestions/derive-clone-for-eq.stderr b/tests/ui/suggestions/derive-clone-for-eq.stderr
index 680890e880c..6fae6e1316d 100644
--- a/tests/ui/suggestions/derive-clone-for-eq.stderr
+++ b/tests/ui/suggestions/derive-clone-for-eq.stderr
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `T: Clone` is not satisfied
   --> $DIR/derive-clone-for-eq.rs:4:17
    |
 LL | #[derive(Clone, Eq)]
-   |                 ^^ the trait `Clone` is not implemented for `T`
+   |                 ^^ the trait `Clone` is not implemented for `T`, which is required by `Struct<T>: PartialEq`
    |
 note: required for `Struct<T>` to implement `PartialEq`
   --> $DIR/derive-clone-for-eq.rs:7:19
diff --git a/tests/ui/suggestions/derive-macro-missing-bounds.stderr b/tests/ui/suggestions/derive-macro-missing-bounds.stderr
index bffcb1af487..5da85a9d061 100644
--- a/tests/ui/suggestions/derive-macro-missing-bounds.stderr
+++ b/tests/ui/suggestions/derive-macro-missing-bounds.stderr
@@ -6,7 +6,7 @@ LL |     #[derive(Debug)]
 LL |     struct Outer<T>(Inner<T>);
    |                     ^^^^^^^^ `a::Inner<T>` cannot be formatted using `{:?}`
    |
-   = help: the trait `Debug` is not implemented for `a::Inner<T>`
+   = help: the trait `Debug` is not implemented for `a::Inner<T>`, which is required by `&a::Inner<T>: Debug`
    = note: add `#[derive(Debug)]` to `a::Inner<T>` or manually `impl Debug for a::Inner<T>`
    = note: this error originates in the derive macro `Debug` (in Nightly builds, run with -Z macro-backtrace for more info)
 help: consider annotating `a::Inner<T>` with `#[derive(Debug)]`
@@ -25,7 +25,7 @@ error[E0277]: the trait bound `T: c::Trait` is not satisfied
 LL |     #[derive(Debug)]
    |              ----- in this derive macro expansion
 LL |     struct Outer<T>(Inner<T>);
-   |                     ^^^^^^^^ the trait `c::Trait` is not implemented for `T`
+   |                     ^^^^^^^^ the trait `c::Trait` is not implemented for `T`, which is required by `&c::Inner<T>: Debug`
    |
 note: required for `c::Inner<T>` to implement `Debug`
   --> $DIR/derive-macro-missing-bounds.rs:34:28
@@ -49,7 +49,7 @@ error[E0277]: the trait bound `T: d::Trait` is not satisfied
 LL |     #[derive(Debug)]
    |              ----- in this derive macro expansion
 LL |     struct Outer<T>(Inner<T>);
-   |                     ^^^^^^^^ the trait `d::Trait` is not implemented for `T`
+   |                     ^^^^^^^^ the trait `d::Trait` is not implemented for `T`, which is required by `&d::Inner<T>: Debug`
    |
 note: required for `d::Inner<T>` to implement `Debug`
   --> $DIR/derive-macro-missing-bounds.rs:49:13
@@ -71,7 +71,7 @@ error[E0277]: the trait bound `T: e::Trait` is not satisfied
 LL |     #[derive(Debug)]
    |              ----- in this derive macro expansion
 LL |     struct Outer<T>(Inner<T>);
-   |                     ^^^^^^^^ the trait `e::Trait` is not implemented for `T`
+   |                     ^^^^^^^^ the trait `e::Trait` is not implemented for `T`, which is required by `&e::Inner<T>: Debug`
    |
 note: required for `e::Inner<T>` to implement `Debug`
   --> $DIR/derive-macro-missing-bounds.rs:64:13
@@ -93,7 +93,7 @@ error[E0277]: the trait bound `T: f::Trait` is not satisfied
 LL |     #[derive(Debug)]
    |              ----- in this derive macro expansion
 LL |     struct Outer<T>(Inner<T>);
-   |                     ^^^^^^^^ the trait `f::Trait` is not implemented for `T`
+   |                     ^^^^^^^^ the trait `f::Trait` is not implemented for `T`, which is required by `&f::Inner<T>: Debug`
    |
 note: required for `f::Inner<T>` to implement `Debug`
   --> $DIR/derive-macro-missing-bounds.rs:79:20
diff --git a/tests/ui/suggestions/into-str.stderr b/tests/ui/suggestions/into-str.stderr
index d6efc8173cb..d10a294c7d2 100644
--- a/tests/ui/suggestions/into-str.stderr
+++ b/tests/ui/suggestions/into-str.stderr
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `&str: From<String>` is not satisfied
   --> $DIR/into-str.rs:4:9
    |
 LL |     foo(String::new());
-   |     --- ^^^^^^^^^^^^^ the trait `From<String>` is not implemented for `&str`
+   |     --- ^^^^^^^^^^^^^ the trait `From<String>` is not implemented for `&str`, which is required by `String: Into<&str>`
    |     |
    |     required by a bound introduced by this call
    |
diff --git a/tests/ui/suggestions/issue-71394-no-from-impl.stderr b/tests/ui/suggestions/issue-71394-no-from-impl.stderr
index b9b72e0e63f..0f6bfbeec45 100644
--- a/tests/ui/suggestions/issue-71394-no-from-impl.stderr
+++ b/tests/ui/suggestions/issue-71394-no-from-impl.stderr
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `&[i8]: From<&[u8]>` is not satisfied
   --> $DIR/issue-71394-no-from-impl.rs:8:25
    |
 LL |     let _: &[i8] = data.into();
-   |                         ^^^^ the trait `From<&[u8]>` is not implemented for `&[i8]`
+   |                         ^^^^ the trait `From<&[u8]>` is not implemented for `&[i8]`, which is required by `&[u8]: Into<_>`
    |
    = help: the following other types implement trait `From<T>`:
              <[bool; N] as From<Mask<T, N>>>
diff --git a/tests/ui/suggestions/issue-88696.stderr b/tests/ui/suggestions/issue-88696.stderr
index b4f0793c225..a8bc970e055 100644
--- a/tests/ui/suggestions/issue-88696.stderr
+++ b/tests/ui/suggestions/issue-88696.stderr
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `Result<u32, i32>: From<Result<u64, i32>>` is not
   --> $DIR/issue-88696.rs:9:9
    |
 LL |     a().into()
-   |         ^^^^ the trait `From<Result<u64, i32>>` is not implemented for `Result<u32, i32>`
+   |         ^^^^ the trait `From<Result<u64, i32>>` is not implemented for `Result<u32, i32>`, which is required by `Result<u64, i32>: Into<_>`
    |
    = note: required for `Result<u64, i32>` to implement `Into<Result<u32, i32>>`
 
diff --git a/tests/ui/suggestions/issue-96223.stderr b/tests/ui/suggestions/issue-96223.stderr
index a54a4e7b3be..4a77b240f3e 100644
--- a/tests/ui/suggestions/issue-96223.stderr
+++ b/tests/ui/suggestions/issue-96223.stderr
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `for<'de> EmptyBis<'de>: Foo<'_>` is not satisfied
   --> $DIR/issue-96223.rs:49:17
    |
 LL |     icey_bounds(&p);
-   |     ----------- ^^ the trait `for<'de> Foo<'_>` is not implemented for `EmptyBis<'de>`
+   |     ----------- ^^ the trait `for<'de> Foo<'_>` is not implemented for `EmptyBis<'de>`, which is required by `Empty: Dummy<EmptyMarker>`
    |     |
    |     required by a bound introduced by this call
    |
diff --git a/tests/ui/suggestions/issue-96555.stderr b/tests/ui/suggestions/issue-96555.stderr
index 1a1e069f09e..f77681ae80f 100644
--- a/tests/ui/suggestions/issue-96555.stderr
+++ b/tests/ui/suggestions/issue-96555.stderr
@@ -6,7 +6,7 @@ LL |     m::f1().await;
    |     |
    |     this call returns `()`
    |
-   = help: the trait `Future` is not implemented for `()`
+   = help: the trait `Future` is not implemented for `()`, which is required by `(): IntoFuture`
    = note: () must be a future or must implement `IntoFuture` to be awaited
    = note: required for `()` to implement `IntoFuture`
 help: remove the `.await`
@@ -27,7 +27,7 @@ LL |     m::f2().await;
    |     |
    |     this call returns `()`
    |
-   = help: the trait `Future` is not implemented for `()`
+   = help: the trait `Future` is not implemented for `()`, which is required by `(): IntoFuture`
    = note: () must be a future or must implement `IntoFuture` to be awaited
    = note: required for `()` to implement `IntoFuture`
 help: remove the `.await`
@@ -48,7 +48,7 @@ LL |     m::f3().await;
    |     |
    |     this call returns `()`
    |
-   = help: the trait `Future` is not implemented for `()`
+   = help: the trait `Future` is not implemented for `()`, which is required by `(): IntoFuture`
    = note: () must be a future or must implement `IntoFuture` to be awaited
    = note: required for `()` to implement `IntoFuture`
 help: remove the `.await`
diff --git a/tests/ui/suggestions/path-by-value.stderr b/tests/ui/suggestions/path-by-value.stderr
index 567d9d5b9e7..46002d4e257 100644
--- a/tests/ui/suggestions/path-by-value.stderr
+++ b/tests/ui/suggestions/path-by-value.stderr
@@ -4,7 +4,7 @@ error[E0277]: the size for values of type `[u8]` cannot be known at compilation
 LL | fn f(p: Path) { }
    |      ^ doesn't have a size known at compile-time
    |
-   = help: within `Path`, the trait `Sized` is not implemented for `[u8]`
+   = help: within `Path`, the trait `Sized` is not implemented for `[u8]`, which is required by `Path: Sized`
 note: required because it appears within the type `Path`
   --> $SRC_DIR/std/src/path.rs:LL:COL
    = help: unsized fn params are gated as an unstable feature
diff --git a/tests/ui/suggestions/path-display.stderr b/tests/ui/suggestions/path-display.stderr
index 46d0b35825b..f9159c45030 100644
--- a/tests/ui/suggestions/path-display.stderr
+++ b/tests/ui/suggestions/path-display.stderr
@@ -4,7 +4,7 @@ error[E0277]: `Path` doesn't implement `std::fmt::Display`
 LL |     println!("{}", path);
    |                    ^^^^ `Path` cannot be formatted with the default formatter; call `.display()` on it
    |
-   = help: the trait `std::fmt::Display` is not implemented for `Path`
+   = help: the trait `std::fmt::Display` is not implemented for `Path`, which is required by `&Path: std::fmt::Display`
    = note: in format strings you may be able to use `{:?}` (or {:#?} for pretty-print) instead
    = note: call `.display()` or `.to_string_lossy()` to safely print paths, as they may contain non-Unicode data
    = note: this error originates in the macro `$crate::format_args_nl` which comes from the expansion of the macro `println` (in Nightly builds, run with -Z macro-backtrace for more info)
diff --git a/tests/ui/suggestions/suggest-dereferencing-index.stderr b/tests/ui/suggestions/suggest-dereferencing-index.stderr
index 2316acbe9da..86487cdcc44 100644
--- a/tests/ui/suggestions/suggest-dereferencing-index.stderr
+++ b/tests/ui/suggestions/suggest-dereferencing-index.stderr
@@ -4,7 +4,7 @@ error[E0277]: the type `[{integer}]` cannot be indexed by `&usize`
 LL |     let one_item_please: i32 = [1, 2, 3][i];
    |                                          ^ slice indices are of type `usize` or ranges of `usize`
    |
-   = help: the trait `SliceIndex<[{integer}]>` is not implemented for `&usize`
+   = help: the trait `SliceIndex<[{integer}]>` is not implemented for `&usize`, which is required by `[{integer}; 3]: Index<_>`
    = help: the trait `SliceIndex<[{integer}]>` is implemented for `usize`
    = help: for that trait implementation, expected `usize`, found `&usize`
    = note: required for `[{integer}]` to implement `Index<&usize>`
diff --git a/tests/ui/suggestions/suggest-pin-macro.stderr b/tests/ui/suggestions/suggest-pin-macro.stderr
index a761a454ad5..68f4099a976 100644
--- a/tests/ui/suggestions/suggest-pin-macro.stderr
+++ b/tests/ui/suggestions/suggest-pin-macro.stderr
@@ -2,7 +2,7 @@ error[E0277]: `PhantomPinned` cannot be unpinned
   --> $DIR/suggest-pin-macro.rs:22:17
    |
 LL |     dummy(test1.get_mut());
-   |                 ^^^^^^^ within `Test`, the trait `Unpin` is not implemented for `PhantomPinned`
+   |                 ^^^^^^^ within `Test`, the trait `Unpin` is not implemented for `PhantomPinned`, which is required by `Test: Unpin`
    |
    = note: consider using the `pin!` macro
            consider using `Box::pin` if you need to access the pinned value outside of the current scope
diff --git a/tests/ui/suggestions/suggest-remove-refs-1.stderr b/tests/ui/suggestions/suggest-remove-refs-1.stderr
index 523f78dffcc..171184bf77d 100644
--- a/tests/ui/suggestions/suggest-remove-refs-1.stderr
+++ b/tests/ui/suggestions/suggest-remove-refs-1.stderr
@@ -4,7 +4,7 @@ error[E0277]: `&Enumerate<std::slice::Iter<'_, {integer}>>` is not an iterator
 LL |     for (i, _) in &v.iter().enumerate() {
    |                   ^^^^^^^^^^^^^^^^^^^^^ `&Enumerate<std::slice::Iter<'_, {integer}>>` is not an iterator
    |
-   = help: the trait `Iterator` is not implemented for `&Enumerate<std::slice::Iter<'_, {integer}>>`
+   = help: the trait `Iterator` is not implemented for `&Enumerate<std::slice::Iter<'_, {integer}>>`, which is required by `&Enumerate<std::slice::Iter<'_, {integer}>>: IntoIterator`
    = note: required for `&Enumerate<std::slice::Iter<'_, {integer}>>` to implement `IntoIterator`
 help: consider removing the leading `&`-reference
    |
diff --git a/tests/ui/suggestions/suggest-remove-refs-2.stderr b/tests/ui/suggestions/suggest-remove-refs-2.stderr
index bbe3261e148..4e1994523dc 100644
--- a/tests/ui/suggestions/suggest-remove-refs-2.stderr
+++ b/tests/ui/suggestions/suggest-remove-refs-2.stderr
@@ -4,7 +4,7 @@ error[E0277]: `&&&&&Enumerate<std::slice::Iter<'_, {integer}>>` is not an iterat
 LL |     for (i, _) in & & & & &v.iter().enumerate() {
    |                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `&&&&&Enumerate<std::slice::Iter<'_, {integer}>>` is not an iterator
    |
-   = help: the trait `Iterator` is not implemented for `&&&&&Enumerate<std::slice::Iter<'_, {integer}>>`
+   = help: the trait `Iterator` is not implemented for `&&&&&Enumerate<std::slice::Iter<'_, {integer}>>`, which is required by `&&&&&Enumerate<std::slice::Iter<'_, {integer}>>: IntoIterator`
    = note: required for `&&&&&Enumerate<std::slice::Iter<'_, {integer}>>` to implement `IntoIterator`
 help: consider removing 5 leading `&`-references
    |
diff --git a/tests/ui/suggestions/suggest-remove-refs-3.stderr b/tests/ui/suggestions/suggest-remove-refs-3.stderr
index a3e142563ff..1d180f9d8be 100644
--- a/tests/ui/suggestions/suggest-remove-refs-3.stderr
+++ b/tests/ui/suggestions/suggest-remove-refs-3.stderr
@@ -8,7 +8,7 @@ LL | |         .iter()
 LL | |         .enumerate() {
    | |____________________^ `&&&&&Enumerate<std::slice::Iter<'_, {integer}>>` is not an iterator
    |
-   = help: the trait `Iterator` is not implemented for `&&&&&Enumerate<std::slice::Iter<'_, {integer}>>`
+   = help: the trait `Iterator` is not implemented for `&&&&&Enumerate<std::slice::Iter<'_, {integer}>>`, which is required by `&&&&&Enumerate<std::slice::Iter<'_, {integer}>>: IntoIterator`
    = note: required for `&&&&&Enumerate<std::slice::Iter<'_, {integer}>>` to implement `IntoIterator`
 help: consider removing 5 leading `&`-references
    |
diff --git a/tests/ui/suggestions/suggest-remove-refs-4.stderr b/tests/ui/suggestions/suggest-remove-refs-4.stderr
index ed9fc2dd256..7ab34c4af51 100644
--- a/tests/ui/suggestions/suggest-remove-refs-4.stderr
+++ b/tests/ui/suggestions/suggest-remove-refs-4.stderr
@@ -4,7 +4,7 @@ error[E0277]: `&&std::slice::Iter<'_, {integer}>` is not an iterator
 LL |     for _i in &foo {}
    |               ^^^^ `&&std::slice::Iter<'_, {integer}>` is not an iterator
    |
-   = help: the trait `Iterator` is not implemented for `&&std::slice::Iter<'_, {integer}>`
+   = help: the trait `Iterator` is not implemented for `&&std::slice::Iter<'_, {integer}>`, which is required by `&&std::slice::Iter<'_, {integer}>: IntoIterator`
    = note: required for `&&std::slice::Iter<'_, {integer}>` to implement `IntoIterator`
 help: consider removing 2 leading `&`-references
    |
diff --git a/tests/ui/suggestions/suggest-remove-refs-5.stderr b/tests/ui/suggestions/suggest-remove-refs-5.stderr
index 7de84d6122b..6b2f330e1a3 100644
--- a/tests/ui/suggestions/suggest-remove-refs-5.stderr
+++ b/tests/ui/suggestions/suggest-remove-refs-5.stderr
@@ -4,7 +4,7 @@ error[E0277]: `Vec<i32>` is not an iterator
 LL |     for _ in &mut &mut v {}
    |              ^^^^^^^^^^^ `Vec<i32>` is not an iterator; try calling `.into_iter()` or `.iter()`
    |
-   = help: the trait `Iterator` is not implemented for `Vec<i32>`
+   = help: the trait `Iterator` is not implemented for `Vec<i32>`, which is required by `&mut &mut &mut &mut Vec<i32>: IntoIterator`
    = note: required for `&mut Vec<i32>` to implement `Iterator`
    = note: 3 redundant requirements hidden
    = note: required for `&mut &mut &mut &mut Vec<i32>` to implement `Iterator`
@@ -21,7 +21,7 @@ error[E0277]: `[u8; 1]` is not an iterator
 LL |     for _ in &mut v {}
    |              ^^^^^^ `[u8; 1]` is not an iterator; try calling `.into_iter()` or `.iter()`
    |
-   = help: the trait `Iterator` is not implemented for `[u8; 1]`
+   = help: the trait `Iterator` is not implemented for `[u8; 1]`, which is required by `&mut &mut &mut [u8; 1]: IntoIterator`
    = note: required for `&mut [u8; 1]` to implement `Iterator`
    = note: 2 redundant requirements hidden
    = note: required for `&mut &mut &mut [u8; 1]` to implement `Iterator`
diff --git a/tests/ui/sync/mutexguard-sync.stderr b/tests/ui/sync/mutexguard-sync.stderr
index 1501a793d5e..6b686741d1f 100644
--- a/tests/ui/sync/mutexguard-sync.stderr
+++ b/tests/ui/sync/mutexguard-sync.stderr
@@ -6,7 +6,7 @@ LL |     test_sync(guard);
    |     |
    |     required by a bound introduced by this call
    |
-   = help: the trait `Sync` is not implemented for `Cell<i32>`
+   = help: the trait `Sync` is not implemented for `Cell<i32>`, which is required by `MutexGuard<'_, Cell<i32>>: Sync`
    = note: if you want to do aliasing and mutation between multiple threads, use `std::sync::RwLock` or `std::sync::atomic::AtomicI32` instead
    = note: required for `MutexGuard<'_, Cell<i32>>` to implement `Sync`
 note: required by a bound in `test_sync`
diff --git a/tests/ui/traits/alias/cross-crate.stderr b/tests/ui/traits/alias/cross-crate.stderr
index ae9d7d0a9b4..fd614b4bcd5 100644
--- a/tests/ui/traits/alias/cross-crate.stderr
+++ b/tests/ui/traits/alias/cross-crate.stderr
@@ -4,7 +4,7 @@ error[E0277]: `Rc<u32>` cannot be sent between threads safely
 LL |     use_alias::<Rc<u32>>();
    |                 ^^^^^^^ `Rc<u32>` cannot be sent between threads safely
    |
-   = help: the trait `Send` is not implemented for `Rc<u32>`
+   = help: the trait `Send` is not implemented for `Rc<u32>`, which is required by `Rc<u32>: SendSync`
    = note: required for `Rc<u32>` to implement `SendSync`
 note: required by a bound in `use_alias`
   --> $DIR/cross-crate.rs:10:17
@@ -18,7 +18,7 @@ error[E0277]: `Rc<u32>` cannot be shared between threads safely
 LL |     use_alias::<Rc<u32>>();
    |                 ^^^^^^^ `Rc<u32>` cannot be shared between threads safely
    |
-   = help: the trait `Sync` is not implemented for `Rc<u32>`
+   = help: the trait `Sync` is not implemented for `Rc<u32>`, which is required by `Rc<u32>: SendSync`
    = note: required for `Rc<u32>` to implement `SendSync`
 note: required by a bound in `use_alias`
   --> $DIR/cross-crate.rs:10:17
diff --git a/tests/ui/traits/alias/issue-108072-unmet-trait-alias-bound.stderr b/tests/ui/traits/alias/issue-108072-unmet-trait-alias-bound.stderr
index 968ad2667a2..1e4f4cb7046 100644
--- a/tests/ui/traits/alias/issue-108072-unmet-trait-alias-bound.stderr
+++ b/tests/ui/traits/alias/issue-108072-unmet-trait-alias-bound.stderr
@@ -6,7 +6,7 @@ LL |     f(())
    |     |
    |     required by a bound introduced by this call
    |
-   = help: the trait `Iterator` is not implemented for `()`
+   = help: the trait `Iterator` is not implemented for `()`, which is required by `(): IteratorAlias`
    = note: required for `()` to implement `IteratorAlias`
 note: required by a bound in `f`
   --> $DIR/issue-108072-unmet-trait-alias-bound.rs:7:14
diff --git a/tests/ui/traits/bound/assoc-fn-bound-root-obligation.stderr b/tests/ui/traits/bound/assoc-fn-bound-root-obligation.stderr
index c8631ed3677..bd9838bc623 100644
--- a/tests/ui/traits/bound/assoc-fn-bound-root-obligation.stderr
+++ b/tests/ui/traits/bound/assoc-fn-bound-root-obligation.stderr
@@ -4,7 +4,7 @@ error[E0277]: expected a `FnMut(char)` closure, found `u8`
 LL |     s.strip_suffix(b'\n').unwrap_or(s)
    |       ^^^^^^^^^^^^ expected an `FnMut(char)` closure, found `u8`
    |
-   = help: the trait `FnMut<(char,)>` is not implemented for `u8`
+   = help: the trait `FnMut<(char,)>` is not implemented for `u8`, which is required by `u8: Pattern<'_>`
    = help: the following other types implement trait `Pattern<'a>`:
              char
              [char; N]
diff --git a/tests/ui/traits/copy-impl-cannot-normalize.stderr b/tests/ui/traits/copy-impl-cannot-normalize.stderr
index 3bdb8b70172..a98bb47f54f 100644
--- a/tests/ui/traits/copy-impl-cannot-normalize.stderr
+++ b/tests/ui/traits/copy-impl-cannot-normalize.stderr
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `T: TraitFoo` is not satisfied
   --> $DIR/copy-impl-cannot-normalize.rs:22:18
    |
 LL | impl<T> Copy for Foo<T> {}
-   |                  ^^^^^^ the trait `TraitFoo` is not implemented for `T`
+   |                  ^^^^^^ the trait `TraitFoo` is not implemented for `T`, which is required by `Foo<T>: Clone`
    |
 note: required for `Foo<T>` to implement `Clone`
   --> $DIR/copy-impl-cannot-normalize.rs:12:9
diff --git a/tests/ui/traits/dont-autoderef-ty-with-escaping-var.stderr b/tests/ui/traits/dont-autoderef-ty-with-escaping-var.stderr
index a5d0e6ab095..fecb05cade7 100644
--- a/tests/ui/traits/dont-autoderef-ty-with-escaping-var.stderr
+++ b/tests/ui/traits/dont-autoderef-ty-with-escaping-var.stderr
@@ -8,7 +8,7 @@ error[E0277]: the trait bound `for<'a> &'a mut Vec<&'a u32>: Foo<'static, i32>`
   --> $DIR/dont-autoderef-ty-with-escaping-var.rs:17:6
    |
 LL |     <i32 as RefFoo<i32>>::ref_foo(unknown);
-   |      ^^^ the trait `for<'a> Foo<'static, i32>` is not implemented for `&'a mut Vec<&'a u32>`
+   |      ^^^ the trait `for<'a> Foo<'static, i32>` is not implemented for `&'a mut Vec<&'a u32>`, which is required by `i32: RefFoo<i32>`
    |
 help: this trait has no implementations, consider adding one
   --> $DIR/dont-autoderef-ty-with-escaping-var.rs:3:1
diff --git a/tests/ui/traits/inductive-overflow/supertrait-auto-trait.stderr b/tests/ui/traits/inductive-overflow/supertrait-auto-trait.stderr
index e723c7c5181..629ccac49c5 100644
--- a/tests/ui/traits/inductive-overflow/supertrait-auto-trait.stderr
+++ b/tests/ui/traits/inductive-overflow/supertrait-auto-trait.stderr
@@ -10,7 +10,7 @@ error[E0277]: the trait bound `NoClone: Copy` is not satisfied
   --> $DIR/supertrait-auto-trait.rs:16:23
    |
 LL |     let (a, b) = copy(NoClone);
-   |                  ---- ^^^^^^^ the trait `Copy` is not implemented for `NoClone`
+   |                  ---- ^^^^^^^ the trait `Copy` is not implemented for `NoClone`, which is required by `NoClone: Magic`
    |                  |
    |                  required by a bound introduced by this call
    |
diff --git a/tests/ui/traits/issue-102989.rs b/tests/ui/traits/issue-102989.rs
deleted file mode 100644
index f1ecee0a552..00000000000
--- a/tests/ui/traits/issue-102989.rs
+++ /dev/null
@@ -1,15 +0,0 @@
-// normalize-stderr-test "loaded from .*libcore-.*.rlib" -> "loaded from SYSROOT/libcore-*.rlib"
-
-#![feature(lang_items)]
-#[lang="sized"]
-trait Sized { } //~ ERROR found duplicate lang item `sized`
-
-fn ref_Struct(self: &Struct, f: &u32) -> &u32 {
-    //~^ ERROR `self` parameter is only allowed in associated functions
-    //~| ERROR cannot find type `Struct` in this scope
-    //~| ERROR mismatched types
-    let x = x << 1;
-    //~^ ERROR cannot find value `x` in this scope
-}
-
-fn main() {}
diff --git a/tests/ui/traits/issue-102989.stderr b/tests/ui/traits/issue-102989.stderr
deleted file mode 100644
index 40e49df2b2d..00000000000
--- a/tests/ui/traits/issue-102989.stderr
+++ /dev/null
@@ -1,48 +0,0 @@
-error: `self` parameter is only allowed in associated functions
-  --> $DIR/issue-102989.rs:7:15
-   |
-LL | fn ref_Struct(self: &Struct, f: &u32) -> &u32 {
-   |               ^^^^ not semantically valid as function parameter
-   |
-   = note: associated functions are those in `impl` or `trait` definitions
-
-error[E0412]: cannot find type `Struct` in this scope
-  --> $DIR/issue-102989.rs:7:22
-   |
-LL | fn ref_Struct(self: &Struct, f: &u32) -> &u32 {
-   |                      ^^^^^^ not found in this scope
-
-error[E0425]: cannot find value `x` in this scope
-  --> $DIR/issue-102989.rs:11:13
-   |
-LL |     let x = x << 1;
-   |             ^ help: a local variable with a similar name exists: `f`
-
-error[E0152]: found duplicate lang item `sized`
-  --> $DIR/issue-102989.rs:5:1
-   |
-LL | trait Sized { }
-   | ^^^^^^^^^^^^^^^
-   |
-   = note: the lang item is first defined in crate `core` (which `std` depends on)
-   = note: first definition in `core` loaded from SYSROOT/libcore-*.rlib
-   = note: second definition in the local crate (`issue_102989`)
-
-error[E0308]: mismatched types
-  --> $DIR/issue-102989.rs:7:42
-   |
-LL | fn ref_Struct(self: &Struct, f: &u32) -> &u32 {
-   |    ----------                            ^^^^ expected `&u32`, found `()`
-   |    |
-   |    implicitly returns `()` as its body has no tail or `return` expression
-   |
-help: consider returning the local binding `f`
-   |
-LL ~     let x = x << 1;
-LL +     f
-   |
-
-error: aborting due to 5 previous errors
-
-Some errors have detailed explanations: E0152, E0308, E0412, E0425.
-For more information about an error, try `rustc --explain E0152`.
diff --git a/tests/ui/traits/issue-43784-supertrait.stderr b/tests/ui/traits/issue-43784-supertrait.stderr
index 2bf365745a6..4c565c3fa1d 100644
--- a/tests/ui/traits/issue-43784-supertrait.stderr
+++ b/tests/ui/traits/issue-43784-supertrait.stderr
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `T: Copy` is not satisfied
   --> $DIR/issue-43784-supertrait.rs:8:22
    |
 LL | impl<T> Complete for T {}
-   |                      ^ the trait `Copy` is not implemented for `T`
+   |                      ^ the trait `Copy` is not implemented for `T`, which is required by `T: Partial`
    |
 note: required for `T` to implement `Partial`
   --> $DIR/issue-43784-supertrait.rs:1:11
diff --git a/tests/ui/traits/issue-7013.stderr b/tests/ui/traits/issue-7013.stderr
index 17493663172..5067c7d7dd7 100644
--- a/tests/ui/traits/issue-7013.stderr
+++ b/tests/ui/traits/issue-7013.stderr
@@ -4,7 +4,7 @@ error[E0277]: `Rc<RefCell<A>>` cannot be sent between threads safely
 LL |     let a = A {v: Box::new(B{v: None}) as Box<dyn Foo + Send>};
    |                   ^^^^^^^^^^^^^^^^^^^^ `Rc<RefCell<A>>` cannot be sent between threads safely
    |
-   = help: within `B`, the trait `Send` is not implemented for `Rc<RefCell<A>>`
+   = help: within `B`, the trait `Send` is not implemented for `Rc<RefCell<A>>`, which is required by `B: Send`
 note: required because it appears within the type `Option<Rc<RefCell<A>>>`
   --> $SRC_DIR/core/src/option.rs:LL:COL
 note: required because it appears within the type `B`
diff --git a/tests/ui/traits/issue-71036.stderr b/tests/ui/traits/issue-71036.stderr
index 2452731f19f..35d543eb017 100644
--- a/tests/ui/traits/issue-71036.stderr
+++ b/tests/ui/traits/issue-71036.stderr
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `&'a T: Unsize<&'a U>` is not satisfied
   --> $DIR/issue-71036.rs:11:1
    |
 LL | impl<'a, T: ?Sized + Unsize<U>, U: ?Sized> DispatchFromDyn<Foo<'a, U>> for Foo<'a, T> {}
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Unsize<&'a U>` is not implemented for `&'a T`
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Unsize<&'a U>` is not implemented for `&'a T`, which is required by `&'a &'a T: DispatchFromDyn<&'a &'a U>`
    |
    = note: all implementations of `Unsize` are provided automatically by the compiler, see <https://doc.rust-lang.org/stable/std/marker/trait.Unsize.html> for more information
    = note: required for `&'a &'a T` to implement `DispatchFromDyn<&'a &'a U>`
diff --git a/tests/ui/traits/issue-71136.stderr b/tests/ui/traits/issue-71136.stderr
index 2c03c6bf08e..d37ad8ae34d 100644
--- a/tests/ui/traits/issue-71136.stderr
+++ b/tests/ui/traits/issue-71136.stderr
@@ -5,7 +5,7 @@ LL | #[derive(Clone)]
    |          ----- in this derive macro expansion
 LL | struct FooHolster {
 LL |     the_foos: Vec<Foo>,
-   |     ^^^^^^^^^^^^^^^^^^ the trait `Clone` is not implemented for `Foo`
+   |     ^^^^^^^^^^^^^^^^^^ the trait `Clone` is not implemented for `Foo`, which is required by `Vec<Foo>: Clone`
    |
    = note: required for `Vec<Foo>` to implement `Clone`
    = note: this error originates in the derive macro `Clone` (in Nightly builds, run with -Z macro-backtrace for more info)
diff --git a/tests/ui/traits/issue-91594.stderr b/tests/ui/traits/issue-91594.stderr
index 13568179e81..726ee5b6146 100644
--- a/tests/ui/traits/issue-91594.stderr
+++ b/tests/ui/traits/issue-91594.stderr
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `Foo: HasComponent<()>` is not satisfied
   --> $DIR/issue-91594.rs:10:19
    |
 LL | impl HasComponent<<Foo as Component<Foo>>::Interface> for Foo {}
-   |                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `HasComponent<()>` is not implemented for `Foo`
+   |                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `HasComponent<()>` is not implemented for `Foo`, which is required by `Foo: Component<Foo>`
    |
    = help: the trait `HasComponent<<Foo as Component<Foo>>::Interface>` is implemented for `Foo`
 note: required for `Foo` to implement `Component<Foo>`
diff --git a/tests/ui/traits/issue-97576.stderr b/tests/ui/traits/issue-97576.stderr
index 2c6cfd83b95..bee254461f1 100644
--- a/tests/ui/traits/issue-97576.stderr
+++ b/tests/ui/traits/issue-97576.stderr
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `String: From<impl ToString>` is not satisfied
   --> $DIR/issue-97576.rs:8:22
    |
 LL |             bar: bar.into(),
-   |                      ^^^^ the trait `From<impl ToString>` is not implemented for `String`
+   |                      ^^^^ the trait `From<impl ToString>` is not implemented for `String`, which is required by `impl ToString: Into<_>`
    |
    = note: required for `impl ToString` to implement `Into<String>`
 
diff --git a/tests/ui/traits/negative-impls/negated-auto-traits-error.stderr b/tests/ui/traits/negative-impls/negated-auto-traits-error.stderr
index 8f5b937e586..2a3833beb26 100644
--- a/tests/ui/traits/negative-impls/negated-auto-traits-error.stderr
+++ b/tests/ui/traits/negative-impls/negated-auto-traits-error.stderr
@@ -49,7 +49,7 @@ LL |     is_send((8, TestType));
    |     |
    |     required by a bound introduced by this call
    |
-   = help: within `({integer}, dummy1c::TestType)`, the trait `Send` is not implemented for `dummy1c::TestType`
+   = help: within `({integer}, dummy1c::TestType)`, the trait `Send` is not implemented for `dummy1c::TestType`, which is required by `({integer}, dummy1c::TestType): Send`
    = note: required because it appears within the type `({integer}, dummy1c::TestType)`
 note: required by a bound in `is_send`
   --> $DIR/negated-auto-traits-error.rs:16:15
@@ -87,7 +87,7 @@ LL |     is_send(Box::new(Outer2(TestType)));
    |     |
    |     required by a bound introduced by this call
    |
-   = help: within `Outer2<dummy3::TestType>`, the trait `Send` is not implemented for `dummy3::TestType`
+   = help: within `Outer2<dummy3::TestType>`, the trait `Send` is not implemented for `dummy3::TestType`, which is required by `Box<Outer2<dummy3::TestType>>: Send`
 note: required because it appears within the type `Outer2<dummy3::TestType>`
   --> $DIR/negated-auto-traits-error.rs:12:8
    |
@@ -110,7 +110,7 @@ LL |     is_sync(Outer2(TestType));
    |     |
    |     required by a bound introduced by this call
    |
-   = help: the trait `Send` is not implemented for `main::TestType`
+   = help: the trait `Send` is not implemented for `main::TestType`, which is required by `Outer2<main::TestType>: Sync`
 note: required for `Outer2<main::TestType>` to implement `Sync`
   --> $DIR/negated-auto-traits-error.rs:14:22
    |
diff --git a/tests/ui/traits/non_lifetime_binders/bad-sized-cond.stderr b/tests/ui/traits/non_lifetime_binders/bad-sized-cond.stderr
index f4deb169516..f7d5d6fcee4 100644
--- a/tests/ui/traits/non_lifetime_binders/bad-sized-cond.stderr
+++ b/tests/ui/traits/non_lifetime_binders/bad-sized-cond.stderr
@@ -29,7 +29,7 @@ error[E0277]: `V` is not an iterator
 LL |     bar();
    |     ^^^^^ `V` is not an iterator
    |
-   = help: the trait `Iterator` is not implemented for `V`
+   = help: the trait `Iterator` is not implemented for `V`, which is required by `V: IntoIterator`
    = note: required for `V` to implement `IntoIterator`
 note: required by a bound in `bar`
   --> $DIR/bad-sized-cond.rs:12:15
@@ -46,7 +46,7 @@ error[E0277]: the size for values of type `V` cannot be known at compilation tim
 LL |     bar();
    |     ^^^^^ doesn't have a size known at compile-time
    |
-   = help: the trait `Sized` is not implemented for `V`
+   = help: the trait `Sized` is not implemented for `V`, which is required by `V: IntoIterator`
    = note: required for `V` to implement `IntoIterator`
 note: required by a bound in `bar`
   --> $DIR/bad-sized-cond.rs:12:15
diff --git a/tests/ui/traits/question-mark-result-err-mismatch.stderr b/tests/ui/traits/question-mark-result-err-mismatch.stderr
index 3059e0beca3..79f270fd1bb 100644
--- a/tests/ui/traits/question-mark-result-err-mismatch.stderr
+++ b/tests/ui/traits/question-mark-result-err-mismatch.stderr
@@ -11,7 +11,7 @@ LL | |             e;
 LL | |         })
    | |__________- this can't be annotated with `?` because it has type `Result<_, ()>`
 LL |           .map(|()| "")?;
-   |                        ^ the trait `From<()>` is not implemented for `String`
+   |                        ^ the trait `From<()>` is not implemented for `String`, which is required by `Result<String, String>: FromResidual<Result<Infallible, ()>>`
    |
    = note: the question mark operation (`?`) implicitly performs a conversion on the error value using the `From` trait
    = note: required for `Result<String, String>` to implement `FromResidual<Result<Infallible, ()>>`
@@ -25,7 +25,7 @@ LL |     let x = foo();
    |             ----- this has type `Result<_, String>`
 ...
 LL |         .map_err(|_| ())?;
-   |          ---------------^ the trait `From<()>` is not implemented for `String`
+   |          ---------------^ the trait `From<()>` is not implemented for `String`, which is required by `Result<(), String>: FromResidual<Result<Infallible, ()>>`
    |          |
    |          this can't be annotated with `?` because it has type `Result<_, ()>`
    |
@@ -50,7 +50,7 @@ LL |           .ok_or_else(|| {
 LL | |             "Couldn't split the test string";
    | |                                             - help: remove this semicolon
 LL | |         })?;
-   | |          -^ the trait `From<()>` is not implemented for `String`
+   | |          -^ the trait `From<()>` is not implemented for `String`, which is required by `Result<String, String>: FromResidual<Result<Infallible, ()>>`
    | |__________|
    |            this can't be annotated with `?` because it has type `Result<_, ()>`
    |
diff --git a/tests/ui/traits/suggest-dereferences/dont-suggest-unsize-deref.stderr b/tests/ui/traits/suggest-dereferences/dont-suggest-unsize-deref.stderr
index 8024ad28d5a..28a0646a86b 100644
--- a/tests/ui/traits/suggest-dereferences/dont-suggest-unsize-deref.stderr
+++ b/tests/ui/traits/suggest-dereferences/dont-suggest-unsize-deref.stderr
@@ -6,7 +6,7 @@ LL |     use_iterator(i);
    |     |
    |     required by a bound introduced by this call
    |
-   = help: the trait `Iterator` is not implemented for `&dyn IntoIterator<IntoIter = I, Item = i32>`
+   = help: the trait `Iterator` is not implemented for `&dyn IntoIterator<IntoIter = I, Item = i32>`, which is required by `&dyn IntoIterator<IntoIter = I, Item = i32>: IntoIterator`
    = note: required for `&dyn IntoIterator<IntoIter = I, Item = i32>` to implement `IntoIterator`
 note: required by a bound in `use_iterator`
   --> $DIR/dont-suggest-unsize-deref.rs:3:8
diff --git a/tests/ui/traits/suggest-dereferences/issue-39029.stderr b/tests/ui/traits/suggest-dereferences/issue-39029.stderr
index fd45fa3cf74..0eea6cbcc5a 100644
--- a/tests/ui/traits/suggest-dereferences/issue-39029.stderr
+++ b/tests/ui/traits/suggest-dereferences/issue-39029.stderr
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `NoToSocketAddrs: ToSocketAddrs` is not satisfied
   --> $DIR/issue-39029.rs:16:38
    |
 LL |     let _errors = TcpListener::bind(&bad);
-   |                   -----------------  ^^^ the trait `ToSocketAddrs` is not implemented for `NoToSocketAddrs`
+   |                   -----------------  ^^^ the trait `ToSocketAddrs` is not implemented for `NoToSocketAddrs`, which is required by `&NoToSocketAddrs: ToSocketAddrs`
    |                   |
    |                   required by a bound introduced by this call
    |
diff --git a/tests/ui/traits/suggest-dereferences/root-obligation.stderr b/tests/ui/traits/suggest-dereferences/root-obligation.stderr
index 62500866c49..a41330373be 100644
--- a/tests/ui/traits/suggest-dereferences/root-obligation.stderr
+++ b/tests/ui/traits/suggest-dereferences/root-obligation.stderr
@@ -6,7 +6,7 @@ LL |         .filter(|c| "aeiou".contains(c))
    |                             |
    |                             required by a bound introduced by this call
    |
-   = help: the trait `Fn<(char,)>` is not implemented for `char`
+   = help: the trait `Fn<(char,)>` is not implemented for `char`, which is required by `&char: Pattern<'_>`
    = note: required for `&char` to implement `FnOnce<(char,)>`
    = note: required for `&char` to implement `Pattern<'_>`
 note: required by a bound in `core::str::<impl str>::contains`
diff --git a/tests/ui/traits/suggest-dereferences/suggest-dereferencing-receiver-argument.stderr b/tests/ui/traits/suggest-dereferences/suggest-dereferencing-receiver-argument.stderr
index d6033bc6baa..d1d75625aba 100644
--- a/tests/ui/traits/suggest-dereferences/suggest-dereferencing-receiver-argument.stderr
+++ b/tests/ui/traits/suggest-dereferences/suggest-dereferencing-receiver-argument.stderr
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `TargetStruct: From<&{integer}>` is not satisfied
   --> $DIR/suggest-dereferencing-receiver-argument.rs:13:30
    |
 LL |     let _b: TargetStruct = a.into();
-   |                              ^^^^ the trait `From<&{integer}>` is not implemented for `TargetStruct`
+   |                              ^^^^ the trait `From<&{integer}>` is not implemented for `TargetStruct`, which is required by `&{integer}: Into<_>`
    |
    = note: required for `&{integer}` to implement `Into<TargetStruct>`
 help: consider dereferencing here
diff --git a/tests/ui/traits/unsend-future.stderr b/tests/ui/traits/unsend-future.stderr
index 25df3419794..4462208cb49 100644
--- a/tests/ui/traits/unsend-future.stderr
+++ b/tests/ui/traits/unsend-future.stderr
@@ -4,7 +4,7 @@ error: future cannot be sent between threads safely
 LL |     require_handler(handler)
    |                     ^^^^^^^ future returned by `handler` is not `Send`
    |
-   = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `*const i32`
+   = help: within `impl Future<Output = ()>`, the trait `Send` is not implemented for `*const i32`, which is required by `fn() -> impl Future<Output = ()> {handler}: Handler`
 note: future is not `Send` as this value is used across an await
   --> $DIR/unsend-future.rs:15:14
    |
diff --git a/tests/ui/try-block/try-block-bad-type.stderr b/tests/ui/try-block/try-block-bad-type.stderr
index d58a011ff55..6c41b42dc64 100644
--- a/tests/ui/try-block/try-block-bad-type.stderr
+++ b/tests/ui/try-block/try-block-bad-type.stderr
@@ -2,7 +2,7 @@ error[E0277]: `?` couldn't convert the error to `TryFromSliceError`
   --> $DIR/try-block-bad-type.rs:7:16
    |
 LL |         Err("")?;
-   |         -------^ the trait `From<&str>` is not implemented for `TryFromSliceError`
+   |         -------^ the trait `From<&str>` is not implemented for `TryFromSliceError`, which is required by `Result<u32, TryFromSliceError>: FromResidual<Result<Infallible, &str>>`
    |         |
    |         this can't be annotated with `?` because it has type `Result<_, &str>`
    |
diff --git a/tests/ui/try-trait/bad-interconversion.stderr b/tests/ui/try-trait/bad-interconversion.stderr
index 7e5b68353fb..80471c0ab1a 100644
--- a/tests/ui/try-trait/bad-interconversion.stderr
+++ b/tests/ui/try-trait/bad-interconversion.stderr
@@ -4,7 +4,7 @@ error[E0277]: `?` couldn't convert the error to `u8`
 LL | fn result_to_result() -> Result<u64, u8> {
    |                          --------------- expected `u8` because of this
 LL |     Ok(Err(123_i32)?)
-   |        ------------^ the trait `From<i32>` is not implemented for `u8`
+   |        ------------^ the trait `From<i32>` is not implemented for `u8`, which is required by `Result<u64, u8>: FromResidual<Result<Infallible, i32>>`
    |        |
    |        this can't be annotated with `?` because it has type `Result<_, i32>`
    |
diff --git a/tests/ui/try-trait/issue-32709.stderr b/tests/ui/try-trait/issue-32709.stderr
index b155b3ff663..34618de78cd 100644
--- a/tests/ui/try-trait/issue-32709.stderr
+++ b/tests/ui/try-trait/issue-32709.stderr
@@ -4,7 +4,7 @@ error[E0277]: `?` couldn't convert the error to `()`
 LL | fn a() -> Result<i32, ()> {
    |           --------------- expected `()` because of this
 LL |     Err(5)?;
-   |     ------^ the trait `From<{integer}>` is not implemented for `()`
+   |     ------^ the trait `From<{integer}>` is not implemented for `()`, which is required by `Result<i32, ()>: FromResidual<Result<Infallible, {integer}>>`
    |     |
    |     this can't be annotated with `?` because it has type `Result<_, {integer}>`
    |
diff --git a/tests/ui/type-alias-impl-trait/auto-trait-leakage2.stderr b/tests/ui/type-alias-impl-trait/auto-trait-leakage2.stderr
index 2ed918eca17..5c5506fb853 100644
--- a/tests/ui/type-alias-impl-trait/auto-trait-leakage2.stderr
+++ b/tests/ui/type-alias-impl-trait/auto-trait-leakage2.stderr
@@ -9,7 +9,7 @@ LL |     is_send(m::foo());
    |     |
    |     required by a bound introduced by this call
    |
-   = help: within `Foo`, the trait `Send` is not implemented for `Rc<u32>`
+   = help: within `Foo`, the trait `Send` is not implemented for `Rc<u32>`, which is required by `Foo: Send`
 note: required because it appears within the type `Foo`
   --> $DIR/auto-trait-leakage2.rs:7:16
    |
diff --git a/tests/ui/type-alias-impl-trait/issue-90400-2.stderr b/tests/ui/type-alias-impl-trait/issue-90400-2.stderr
index 37abb3fe021..5e978e97d6b 100644
--- a/tests/ui/type-alias-impl-trait/issue-90400-2.stderr
+++ b/tests/ui/type-alias-impl-trait/issue-90400-2.stderr
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `B: Bar` is not satisfied
   --> $DIR/issue-90400-2.rs:25:9
    |
 LL |         MyBaz(bar)
-   |         ^^^^^^^^^^ the trait `Bar` is not implemented for `B`
+   |         ^^^^^^^^^^ the trait `Bar` is not implemented for `B`, which is required by `MyBaz<B>: Baz`
    |
 note: required for `MyBaz<B>` to implement `Baz`
   --> $DIR/issue-90400-2.rs:30:14
diff --git a/tests/ui/type-alias-impl-trait/multiple-def-uses-in-one-fn.stderr b/tests/ui/type-alias-impl-trait/multiple-def-uses-in-one-fn.stderr
index b5f38074632..a7840e0a5bf 100644
--- a/tests/ui/type-alias-impl-trait/multiple-def-uses-in-one-fn.stderr
+++ b/tests/ui/type-alias-impl-trait/multiple-def-uses-in-one-fn.stderr
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `&'static B: From<&A>` is not satisfied
   --> $DIR/multiple-def-uses-in-one-fn.rs:9:45
    |
 LL | fn f<A, B: 'static>(a: &'static A, b: B) -> (X<A, B>, X<B, A>) {
-   |                                             ^^^^^^^^^^^^^^^^^^ the trait `From<&A>` is not implemented for `&'static B`
+   |                                             ^^^^^^^^^^^^^^^^^^ the trait `From<&A>` is not implemented for `&'static B`, which is required by `&A: Into<&'static B>`
    |
    = note: required for `&A` to implement `Into<&'static B>`
 help: consider introducing a `where` clause, but there might be an alternative better way to express this requirement
diff --git a/tests/ui/type-alias-impl-trait/underconstrained_generic.stderr b/tests/ui/type-alias-impl-trait/underconstrained_generic.stderr
index e4de9245951..913a35eb9fb 100644
--- a/tests/ui/type-alias-impl-trait/underconstrained_generic.stderr
+++ b/tests/ui/type-alias-impl-trait/underconstrained_generic.stderr
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `T: Trait` is not satisfied
   --> $DIR/underconstrained_generic.rs:22:5
    |
 LL |     ()
-   |     ^^ the trait `Trait` is not implemented for `T`
+   |     ^^ the trait `Trait` is not implemented for `T`, which is required by `(): ProofForConversion<T>`
    |
 note: required for `()` to implement `ProofForConversion<T>`
   --> $DIR/underconstrained_generic.rs:13:16
diff --git a/tests/ui/type/issue-58355.stderr b/tests/ui/type/issue-58355.stderr
index b6056f0fd65..cd8e3538802 100644
--- a/tests/ui/type/issue-58355.stderr
+++ b/tests/ui/type/issue-58355.stderr
@@ -4,7 +4,7 @@ error[E0277]: the size for values of type `dyn ToString` cannot be known at comp
 LL |     x = Some(Box::new(callback));
    |              ^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
    |
-   = help: within `fn() -> dyn ToString`, the trait `Sized` is not implemented for `dyn ToString`
+   = help: within `fn() -> dyn ToString`, the trait `Sized` is not implemented for `dyn ToString`, which is required by `fn() -> dyn ToString: Fn()`
    = note: required because it appears within the type `fn() -> dyn ToString`
    = note: required for the cast from `Box<fn() -> dyn ToString>` to `Box<dyn Fn() -> (dyn ToString + 'static)>`
 
diff --git a/tests/ui/typeck/bad-index-due-to-nested.stderr b/tests/ui/typeck/bad-index-due-to-nested.stderr
index bd7fd0392c3..137c7b06396 100644
--- a/tests/ui/typeck/bad-index-due-to-nested.stderr
+++ b/tests/ui/typeck/bad-index-due-to-nested.stderr
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `K: Hash` is not satisfied
   --> $DIR/bad-index-due-to-nested.rs:20:5
    |
 LL |     map[k]
-   |     ^^^ the trait `Hash` is not implemented for `K`
+   |     ^^^ the trait `Hash` is not implemented for `K`, which is required by `HashMap<_, _>: Index<&_>`
    |
 note: required for `HashMap<K, V>` to implement `Index<&K>`
   --> $DIR/bad-index-due-to-nested.rs:7:12
@@ -21,7 +21,7 @@ error[E0277]: the trait bound `V: Copy` is not satisfied
   --> $DIR/bad-index-due-to-nested.rs:20:5
    |
 LL |     map[k]
-   |     ^^^ the trait `Copy` is not implemented for `V`
+   |     ^^^ the trait `Copy` is not implemented for `V`, which is required by `HashMap<_, _>: Index<&_>`
    |
 note: required for `HashMap<K, V>` to implement `Index<&K>`
   --> $DIR/bad-index-due-to-nested.rs:7:12
diff --git a/tests/ui/typeck/issue-90101.stderr b/tests/ui/typeck/issue-90101.stderr
index a24f9cb540f..d5ba157974d 100644
--- a/tests/ui/typeck/issue-90101.stderr
+++ b/tests/ui/typeck/issue-90101.stderr
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `PathBuf: From<Cow<'_, str>>` is not satisfied
   --> $DIR/issue-90101.rs:6:10
    |
 LL |     func(Path::new("hello").to_path_buf().to_string_lossy(), "world")
-   |     ---- ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `From<Cow<'_, str>>` is not implemented for `PathBuf`
+   |     ---- ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `From<Cow<'_, str>>` is not implemented for `PathBuf`, which is required by `Cow<'_, str>: Into<PathBuf>`
    |     |
    |     required by a bound introduced by this call
    |
diff --git a/tests/ui/typeck/typeck-default-trait-impl-negation-sync.stderr b/tests/ui/typeck/typeck-default-trait-impl-negation-sync.stderr
index b9fca1a1b54..f5311b6e8ed 100644
--- a/tests/ui/typeck/typeck-default-trait-impl-negation-sync.stderr
+++ b/tests/ui/typeck/typeck-default-trait-impl-negation-sync.stderr
@@ -17,7 +17,7 @@ error[E0277]: `UnsafeCell<u8>` cannot be shared between threads safely
 LL |     is_sync::<MyTypeWUnsafe>();
    |               ^^^^^^^^^^^^^ `UnsafeCell<u8>` cannot be shared between threads safely
    |
-   = help: within `MyTypeWUnsafe`, the trait `Sync` is not implemented for `UnsafeCell<u8>`
+   = help: within `MyTypeWUnsafe`, the trait `Sync` is not implemented for `UnsafeCell<u8>`, which is required by `MyTypeWUnsafe: Sync`
 note: required because it appears within the type `MyTypeWUnsafe`
   --> $DIR/typeck-default-trait-impl-negation-sync.rs:21:8
    |
@@ -35,7 +35,7 @@ error[E0277]: `Managed` cannot be shared between threads safely
 LL |     is_sync::<MyTypeManaged>();
    |               ^^^^^^^^^^^^^ `Managed` cannot be shared between threads safely
    |
-   = help: within `MyTypeManaged`, the trait `Sync` is not implemented for `Managed`
+   = help: within `MyTypeManaged`, the trait `Sync` is not implemented for `Managed`, which is required by `MyTypeManaged: Sync`
 note: required because it appears within the type `MyTypeManaged`
   --> $DIR/typeck-default-trait-impl-negation-sync.rs:25:8
    |
diff --git a/tests/ui/typeck/typeck-unsafe-always-share.stderr b/tests/ui/typeck/typeck-unsafe-always-share.stderr
index 154e504996b..3eb792b82e0 100644
--- a/tests/ui/typeck/typeck-unsafe-always-share.stderr
+++ b/tests/ui/typeck/typeck-unsafe-always-share.stderr
@@ -36,7 +36,7 @@ LL |     test(ms);
    |     |
    |     required by a bound introduced by this call
    |
-   = help: within `MySync<NoSync>`, the trait `Sync` is not implemented for `UnsafeCell<NoSync>`
+   = help: within `MySync<NoSync>`, the trait `Sync` is not implemented for `UnsafeCell<NoSync>`, which is required by `MySync<NoSync>: Sync`
 note: required because it appears within the type `MySync<NoSync>`
   --> $DIR/typeck-unsafe-always-share.rs:8:8
    |
diff --git a/tests/ui/union/projection-as-union-type-error-2.stderr b/tests/ui/union/projection-as-union-type-error-2.stderr
index 3b073ca1fb4..39cdf30d860 100644
--- a/tests/ui/union/projection-as-union-type-error-2.stderr
+++ b/tests/ui/union/projection-as-union-type-error-2.stderr
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `u8: NotImplemented` is not satisfied
   --> $DIR/projection-as-union-type-error-2.rs:18:8
    |
 LL |     a: <Foo as Identity>::Identity,
-   |        ^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `NotImplemented` is not implemented for `u8`
+   |        ^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `NotImplemented` is not implemented for `u8`, which is required by `u8: Identity`
    |
 help: this trait has no implementations, consider adding one
   --> $DIR/projection-as-union-type-error-2.rs:9:1
diff --git a/tests/ui/unsized-locals/issue-50940-with-feature.stderr b/tests/ui/unsized-locals/issue-50940-with-feature.stderr
index b39eb2e70bb..4c06566709e 100644
--- a/tests/ui/unsized-locals/issue-50940-with-feature.stderr
+++ b/tests/ui/unsized-locals/issue-50940-with-feature.stderr
@@ -13,7 +13,7 @@ error[E0277]: the size for values of type `str` cannot be known at compilation t
 LL |     A as fn(str) -> A<str>;
    |     ^ doesn't have a size known at compile-time
    |
-   = help: within `A<str>`, the trait `Sized` is not implemented for `str`
+   = help: within `A<str>`, the trait `Sized` is not implemented for `str`, which is required by `A<str>: Sized`
 note: required because it appears within the type `A<str>`
   --> $DIR/issue-50940-with-feature.rs:5:12
    |
diff --git a/tests/ui/unsized-locals/rust-call.stderr b/tests/ui/unsized-locals/rust-call.stderr
index 9eb0f3dabcc..b2e13b553e9 100644
--- a/tests/ui/unsized-locals/rust-call.stderr
+++ b/tests/ui/unsized-locals/rust-call.stderr
@@ -4,7 +4,7 @@ error[E0277]: the size for values of type `[u8]` cannot be known at compilation
 LL |     f(*slice);
    |       ^^^^^^ doesn't have a size known at compile-time
    |
-   = help: within `([u8],)`, the trait `Sized` is not implemented for `[u8]`
+   = help: within `([u8],)`, the trait `Sized` is not implemented for `[u8]`, which is required by `([u8],): Sized`
    = note: required because it appears within the type `([u8],)`
    = note: argument required to be sized due to `extern "rust-call"` ABI
 
diff --git a/tests/ui/unsized-locals/unsized-exprs.stderr b/tests/ui/unsized-locals/unsized-exprs.stderr
index 8a2ecf0f6c3..6da37749fac 100644
--- a/tests/ui/unsized-locals/unsized-exprs.stderr
+++ b/tests/ui/unsized-locals/unsized-exprs.stderr
@@ -4,7 +4,7 @@ error[E0277]: the size for values of type `[u8]` cannot be known at compilation
 LL |     udrop::<(i32, [u8])>((42, *foo()));
    |                          ^^^^^^^^^^^^ doesn't have a size known at compile-time
    |
-   = help: within `({integer}, [u8])`, the trait `Sized` is not implemented for `[u8]`
+   = help: within `({integer}, [u8])`, the trait `Sized` is not implemented for `[u8]`, which is required by `({integer}, [u8]): Sized`
    = note: required because it appears within the type `({integer}, [u8])`
    = note: tuples must have a statically known size to be initialized
 
@@ -14,7 +14,7 @@ error[E0277]: the size for values of type `[u8]` cannot be known at compilation
 LL |     udrop::<A<[u8]>>(A { 0: *foo() });
    |                      ^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
    |
-   = help: within `A<[u8]>`, the trait `Sized` is not implemented for `[u8]`
+   = help: within `A<[u8]>`, the trait `Sized` is not implemented for `[u8]`, which is required by `A<[u8]>: Sized`
 note: required because it appears within the type `A<[u8]>`
   --> $DIR/unsized-exprs.rs:3:8
    |
@@ -28,7 +28,7 @@ error[E0277]: the size for values of type `[u8]` cannot be known at compilation
 LL |     udrop::<A<[u8]>>(A(*foo()));
    |                      ^^^^^^^^^ doesn't have a size known at compile-time
    |
-   = help: within `A<[u8]>`, the trait `Sized` is not implemented for `[u8]`
+   = help: within `A<[u8]>`, the trait `Sized` is not implemented for `[u8]`, which is required by `A<[u8]>: Sized`
 note: required because it appears within the type `A<[u8]>`
   --> $DIR/unsized-exprs.rs:3:8
    |
diff --git a/tests/ui/unsized/unsized-enum2.stderr b/tests/ui/unsized/unsized-enum2.stderr
index 71cf782120e..48cca6eb4bd 100644
--- a/tests/ui/unsized/unsized-enum2.stderr
+++ b/tests/ui/unsized/unsized-enum2.stderr
@@ -320,7 +320,7 @@ error[E0277]: the size for values of type `(dyn PathHelper1 + 'static)` cannot b
 LL |     VI(Path1),
    |        ^^^^^ doesn't have a size known at compile-time
    |
-   = help: within `Path1`, the trait `Sized` is not implemented for `(dyn PathHelper1 + 'static)`
+   = help: within `Path1`, the trait `Sized` is not implemented for `(dyn PathHelper1 + 'static)`, which is required by `Path1: Sized`
 note: required because it appears within the type `Path1`
   --> $DIR/unsized-enum2.rs:16:8
    |
@@ -343,7 +343,7 @@ error[E0277]: the size for values of type `(dyn PathHelper2 + 'static)` cannot b
 LL |     VJ{x: Path2},
    |           ^^^^^ doesn't have a size known at compile-time
    |
-   = help: within `Path2`, the trait `Sized` is not implemented for `(dyn PathHelper2 + 'static)`
+   = help: within `Path2`, the trait `Sized` is not implemented for `(dyn PathHelper2 + 'static)`, which is required by `Path2: Sized`
 note: required because it appears within the type `Path2`
   --> $DIR/unsized-enum2.rs:17:8
    |
@@ -366,7 +366,7 @@ error[E0277]: the size for values of type `(dyn PathHelper3 + 'static)` cannot b
 LL |     VK(isize, Path3),
    |               ^^^^^ doesn't have a size known at compile-time
    |
-   = help: within `Path3`, the trait `Sized` is not implemented for `(dyn PathHelper3 + 'static)`
+   = help: within `Path3`, the trait `Sized` is not implemented for `(dyn PathHelper3 + 'static)`, which is required by `Path3: Sized`
 note: required because it appears within the type `Path3`
   --> $DIR/unsized-enum2.rs:18:8
    |
@@ -389,7 +389,7 @@ error[E0277]: the size for values of type `(dyn PathHelper4 + 'static)` cannot b
 LL |     VL{u: isize, x: Path4},
    |                     ^^^^^ doesn't have a size known at compile-time
    |
-   = help: within `Path4`, the trait `Sized` is not implemented for `(dyn PathHelper4 + 'static)`
+   = help: within `Path4`, the trait `Sized` is not implemented for `(dyn PathHelper4 + 'static)`, which is required by `Path4: Sized`
 note: required because it appears within the type `Path4`
   --> $DIR/unsized-enum2.rs:19:8
    |
diff --git a/tests/ui/wf/hir-wf-check-erase-regions.stderr b/tests/ui/wf/hir-wf-check-erase-regions.stderr
index 4b696dc1d1d..93449d60e9d 100644
--- a/tests/ui/wf/hir-wf-check-erase-regions.stderr
+++ b/tests/ui/wf/hir-wf-check-erase-regions.stderr
@@ -4,7 +4,7 @@ error[E0277]: `&'a T` is not an iterator
 LL |     type IntoIter = std::iter::Flatten<std::slice::Iter<'a, T>>;
    |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `&'a T` is not an iterator
    |
-   = help: the trait `Iterator` is not implemented for `&'a T`
+   = help: the trait `Iterator` is not implemented for `&'a T`, which is required by `Flatten<std::slice::Iter<'a, T>>: Iterator`
    = help: the trait `Iterator` is implemented for `&mut I`
    = note: required for `Flatten<std::slice::Iter<'a, T>>` to implement `Iterator`
 note: required by a bound in `std::iter::IntoIterator::IntoIter`
@@ -16,7 +16,7 @@ error[E0277]: `&'a T` is not an iterator
 LL |     type IntoIter = std::iter::Flatten<std::slice::Iter<'a, T>>;
    |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ `&'a T` is not an iterator
    |
-   = help: the trait `Iterator` is not implemented for `&'a T`
+   = help: the trait `Iterator` is not implemented for `&'a T`, which is required by `&'a T: IntoIterator`
    = help: the trait `Iterator` is implemented for `&mut I`
    = note: required for `&'a T` to implement `IntoIterator`
 note: required by a bound in `Flatten`
@@ -28,7 +28,7 @@ error[E0277]: `&'a T` is not an iterator
 LL |     fn into_iter(self) -> Self::IntoIter {
    |                           ^^^^^^^^^^^^^^ `&'a T` is not an iterator
    |
-   = help: the trait `Iterator` is not implemented for `&'a T`
+   = help: the trait `Iterator` is not implemented for `&'a T`, which is required by `&'a T: IntoIterator`
    = help: the trait `Iterator` is implemented for `&mut I`
    = note: required for `&'a T` to implement `IntoIterator`
 note: required by a bound in `Flatten`
diff --git a/tests/ui/wf/wf-const-type.stderr b/tests/ui/wf/wf-const-type.stderr
index 039e907705e..d5e0f7672a6 100644
--- a/tests/ui/wf/wf-const-type.stderr
+++ b/tests/ui/wf/wf-const-type.stderr
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `NotCopy: Copy` is not satisfied
   --> $DIR/wf-const-type.rs:10:12
    |
 LL | const FOO: IsCopy<Option<NotCopy>> = IsCopy { t: None };
-   |            ^^^^^^^^^^^^^^^^^^^^^^^ the trait `Copy` is not implemented for `NotCopy`
+   |            ^^^^^^^^^^^^^^^^^^^^^^^ the trait `Copy` is not implemented for `NotCopy`, which is required by `Option<NotCopy>: Copy`
    |
    = note: required for `Option<NotCopy>` to implement `Copy`
 note: required by a bound in `IsCopy`
@@ -20,7 +20,7 @@ error[E0277]: the trait bound `NotCopy: Copy` is not satisfied
   --> $DIR/wf-const-type.rs:10:50
    |
 LL | const FOO: IsCopy<Option<NotCopy>> = IsCopy { t: None };
-   |                                                  ^^^^ the trait `Copy` is not implemented for `NotCopy`
+   |                                                  ^^^^ the trait `Copy` is not implemented for `NotCopy`, which is required by `Option<NotCopy>: Copy`
    |
    = note: required for `Option<NotCopy>` to implement `Copy`
 note: required by a bound in `IsCopy`
diff --git a/tests/ui/wf/wf-static-type.stderr b/tests/ui/wf/wf-static-type.stderr
index 65dae260143..481173b8a26 100644
--- a/tests/ui/wf/wf-static-type.stderr
+++ b/tests/ui/wf/wf-static-type.stderr
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `NotCopy: Copy` is not satisfied
   --> $DIR/wf-static-type.rs:10:13
    |
 LL | static FOO: IsCopy<Option<NotCopy>> = IsCopy { t: None };
-   |             ^^^^^^^^^^^^^^^^^^^^^^^ the trait `Copy` is not implemented for `NotCopy`
+   |             ^^^^^^^^^^^^^^^^^^^^^^^ the trait `Copy` is not implemented for `NotCopy`, which is required by `Option<NotCopy>: Copy`
    |
    = note: required for `Option<NotCopy>` to implement `Copy`
 note: required by a bound in `IsCopy`
@@ -20,7 +20,7 @@ error[E0277]: the trait bound `NotCopy: Copy` is not satisfied
   --> $DIR/wf-static-type.rs:10:51
    |
 LL | static FOO: IsCopy<Option<NotCopy>> = IsCopy { t: None };
-   |                                                   ^^^^ the trait `Copy` is not implemented for `NotCopy`
+   |                                                   ^^^^ the trait `Copy` is not implemented for `NotCopy`, which is required by `Option<NotCopy>: Copy`
    |
    = note: required for `Option<NotCopy>` to implement `Copy`
 note: required by a bound in `IsCopy`