Auto merge of #134492 - jhpratt:rollup-elpdwd9, r=jhpratt

Rollup of 8 pull requests

Successful merges:

 - #132056 (Stabilize `#[diagnostic::do_not_recommend]`)
 - #133643 (-Znext-solver: modify candidate preference rules)
 - #134388 (Update books)
 - #134418 (Advent of `tests/ui` (misc cleanups and improvements) [3/N])
 - #134473 (chore: fix some typos)
 - #134481 (Point at lint name instead of whole attr for gated lints)
 - #134484 (Add nnethercote to the `triagebot.toml` vacation list.)
 - #134490 (Fix typo in ptr/mod.rs)

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

101 files changed, 718 insertions, 393 deletions

diff --git a/compiler/rustc_codegen_cranelift/src/compiler_builtins.rs b/compiler/rustc_codegen_cranelift/src/compiler_builtins.rs
index 4154a62234c..f8e3a034421 100644
--- a/compiler/rustc_codegen_cranelift/src/compiler_builtins.rs
+++ b/compiler/rustc_codegen_cranelift/src/compiler_builtins.rs
@@ -3,7 +3,7 @@ use std::ffi::c_int;
 #[cfg(feature = "jit")]
 use std::ffi::c_void;
 
-// FIXME replace with core::ffi::c_size_t once stablized
+// FIXME replace with core::ffi::c_size_t once stabilized
 #[allow(non_camel_case_types)]
 #[cfg(feature = "jit")]
 type size_t = usize;
diff --git a/compiler/rustc_codegen_gcc/src/intrinsic/mod.rs b/compiler/rustc_codegen_gcc/src/intrinsic/mod.rs
index 69326f409bb..78ec9741f57 100644
--- a/compiler/rustc_codegen_gcc/src/intrinsic/mod.rs
+++ b/compiler/rustc_codegen_gcc/src/intrinsic/mod.rs
@@ -66,7 +66,7 @@ fn get_simple_intrinsic<'gcc, 'tcx>(
         sym::log2f64 => "log2",
         sym::fmaf32 => "fmaf",
         sym::fmaf64 => "fma",
-        // FIXME: calling `fma` from libc without FMA target feature uses expensive sofware emulation
+        // FIXME: calling `fma` from libc without FMA target feature uses expensive software emulation
         sym::fmuladdf32 => "fmaf", // TODO: use gcc intrinsic analogous to llvm.fmuladd.f32
         sym::fmuladdf64 => "fma",  // TODO: use gcc intrinsic analogous to llvm.fmuladd.f64
         sym::fabsf32 => "fabsf",
diff --git a/compiler/rustc_errors/src/emitter.rs b/compiler/rustc_errors/src/emitter.rs
index ac2f91cdeb3..f63188402fe 100644
--- a/compiler/rustc_errors/src/emitter.rs
+++ b/compiler/rustc_errors/src/emitter.rs
@@ -2523,7 +2523,7 @@ impl HumanEmitter {
                     buffer.puts(*row_num, max_line_num_len + 1, "+ ", Style::Addition);
                 }
                 [] => {
-                    // FIXME: needed? Doesn't get excercised in any test.
+                    // FIXME: needed? Doesn't get exercised in any test.
                     self.draw_col_separator_no_space(buffer, *row_num, max_line_num_len + 1);
                 }
                 _ => {
diff --git a/compiler/rustc_errors/src/markdown/parse.rs b/compiler/rustc_errors/src/markdown/parse.rs
index 8dd146c1c33..7a991a2ace7 100644
--- a/compiler/rustc_errors/src/markdown/parse.rs
+++ b/compiler/rustc_errors/src/markdown/parse.rs
@@ -346,7 +346,7 @@ fn parse_with_end_pat<'a>(
     None
 }
 
-/// Resturn `(match, residual)` to end of line. The EOL is returned with the
+/// Return `(match, residual)` to end of line. The EOL is returned with the
 /// residual.
 fn parse_to_newline(buf: &[u8]) -> (&[u8], &[u8]) {
     buf.iter().position(|ch| *ch == b'\n').map_or((buf, &[]), |pos| buf.split_at(pos))
diff --git a/compiler/rustc_feature/src/accepted.rs b/compiler/rustc_feature/src/accepted.rs
index 21fd11c1c5d..5a9b8c43e74 100644
--- a/compiler/rustc_feature/src/accepted.rs
+++ b/compiler/rustc_feature/src/accepted.rs
@@ -178,6 +178,8 @@ declare_features! (
     (accepted, destructuring_assignment, "1.59.0", Some(71126)),
     /// Allows using the `#[diagnostic]` attribute tool namespace
     (accepted, diagnostic_namespace, "1.78.0", Some(111996)),
+    /// Controls errors in trait implementations.
+    (accepted, do_not_recommend, "CURRENT_RUSTC_VERSION", Some(51992)),
     /// Allows `#[doc(alias = "...")]`.
     (accepted, doc_alias, "1.48.0", Some(50146)),
     /// Allows `..` in tuple (struct) patterns.
diff --git a/compiler/rustc_feature/src/builtin_attrs.rs b/compiler/rustc_feature/src/builtin_attrs.rs
index a065db7f7d0..4b9f62fa764 100644
--- a/compiler/rustc_feature/src/builtin_attrs.rs
+++ b/compiler/rustc_feature/src/builtin_attrs.rs
@@ -1187,10 +1187,9 @@ pub static BUILTIN_ATTRIBUTE_MAP: LazyLock<FxHashMap<Symbol, &BuiltinAttribute>>
         map
     });
 
-pub fn is_stable_diagnostic_attribute(sym: Symbol, features: &Features) -> bool {
+pub fn is_stable_diagnostic_attribute(sym: Symbol, _features: &Features) -> bool {
     match sym {
-        sym::on_unimplemented => true,
-        sym::do_not_recommend => features.do_not_recommend(),
+        sym::on_unimplemented | sym::do_not_recommend => true,
         _ => false,
     }
 }
diff --git a/compiler/rustc_feature/src/unstable.rs b/compiler/rustc_feature/src/unstable.rs
index 6570f9b565f..ebb07195a28 100644
--- a/compiler/rustc_feature/src/unstable.rs
+++ b/compiler/rustc_feature/src/unstable.rs
@@ -462,8 +462,6 @@ declare_features! (
     (unstable, deprecated_suggestion, "1.61.0", Some(94785)),
     /// Allows deref patterns.
     (incomplete, deref_patterns, "1.79.0", Some(87121)),
-    /// Controls errors in trait implementations.
-    (unstable, do_not_recommend, "1.67.0", Some(51992)),
     /// Tells rustdoc to automatically generate `#[doc(cfg(...))]`.
     (unstable, doc_auto_cfg, "1.58.0", Some(43781)),
     /// Allows `#[doc(cfg(...))]`.
diff --git a/compiler/rustc_lint/src/levels.rs b/compiler/rustc_lint/src/levels.rs
index 0185f46c35a..5a4ed68440a 100644
--- a/compiler/rustc_lint/src/levels.rs
+++ b/compiler/rustc_lint/src/levels.rs
@@ -914,7 +914,7 @@ impl<'s, P: LintLevelsProvider> LintLevelsBuilder<'s, P> {
 
                 let src = LintLevelSource::Node { name, span: sp, reason };
                 for &id in ids {
-                    if self.check_gated_lint(id, attr.span(), false) {
+                    if self.check_gated_lint(id, sp, false) {
                         self.insert_spec(id, (level, src));
                     }
                 }
diff --git a/compiler/rustc_middle/src/ty/mod.rs b/compiler/rustc_middle/src/ty/mod.rs
index 25d0d7b71da..830ae7dd00a 100644
--- a/compiler/rustc_middle/src/ty/mod.rs
+++ b/compiler/rustc_middle/src/ty/mod.rs
@@ -971,7 +971,7 @@ pub struct ParamEnv<'tcx> {
 }
 
 impl<'tcx> rustc_type_ir::inherent::ParamEnv<TyCtxt<'tcx>> for ParamEnv<'tcx> {
-    fn caller_bounds(self) -> impl IntoIterator<Item = ty::Clause<'tcx>> {
+    fn caller_bounds(self) -> impl inherent::SliceLike<Item = ty::Clause<'tcx>> {
         self.caller_bounds()
     }
 }
diff --git a/compiler/rustc_next_trait_solver/src/canonicalizer.rs b/compiler/rustc_next_trait_solver/src/canonicalizer.rs
index 63608f9e856..2f7301d8fe5 100644
--- a/compiler/rustc_next_trait_solver/src/canonicalizer.rs
+++ b/compiler/rustc_next_trait_solver/src/canonicalizer.rs
@@ -3,6 +3,7 @@ use std::cmp::Ordering;
 use rustc_type_ir::data_structures::HashMap;
 use rustc_type_ir::fold::{TypeFoldable, TypeFolder, TypeSuperFoldable};
 use rustc_type_ir::inherent::*;
+use rustc_type_ir::solve::{Goal, QueryInput};
 use rustc_type_ir::visit::TypeVisitableExt;
 use rustc_type_ir::{
     self as ty, Canonical, CanonicalTyVarKind, CanonicalVarInfo, CanonicalVarKind, InferCtxtLike,
@@ -17,8 +18,11 @@ use crate::delegate::SolverDelegate;
 /// while canonicalizing the response happens in the context of the
 /// query.
 #[derive(Debug, Clone, Copy)]
-pub enum CanonicalizeMode {
-    Input,
+enum CanonicalizeMode {
+    /// When canonicalizing the `param_env`, we keep `'static` as merging
+    /// trait candidates relies on it when deciding whether a where-bound
+    /// is trivial.
+    Input { keep_static: bool },
     /// FIXME: We currently return region constraints referring to
     /// placeholders and inference variables from a binder instantiated
     /// inside of the query.
@@ -59,15 +63,15 @@ pub struct Canonicalizer<'a, D: SolverDelegate<Interner = I>, I: Interner> {
 }
 
 impl<'a, D: SolverDelegate<Interner = I>, I: Interner> Canonicalizer<'a, D, I> {
-    pub fn canonicalize<T: TypeFoldable<I>>(
+    pub fn canonicalize_response<T: TypeFoldable<I>>(
         delegate: &'a D,
-        canonicalize_mode: CanonicalizeMode,
+        max_input_universe: ty::UniverseIndex,
         variables: &'a mut Vec<I::GenericArg>,
         value: T,
     ) -> ty::Canonical<I, T> {
         let mut canonicalizer = Canonicalizer {
             delegate,
-            canonicalize_mode,
+            canonicalize_mode: CanonicalizeMode::Response { max_input_universe },
 
             variables,
             variable_lookup_table: Default::default(),
@@ -80,9 +84,67 @@ impl<'a, D: SolverDelegate<Interner = I>, I: Interner> Canonicalizer<'a, D, I> {
         let value = value.fold_with(&mut canonicalizer);
         assert!(!value.has_infer(), "unexpected infer in {value:?}");
         assert!(!value.has_placeholders(), "unexpected placeholders in {value:?}");
-
         let (max_universe, variables) = canonicalizer.finalize();
+        Canonical { max_universe, variables, value }
+    }
+
+    /// When canonicalizing query inputs, we keep `'static` in the `param_env`
+    /// but erase it everywhere else. We generally don't want to depend on region
+    /// identity, so while it should not matter whether `'static` is kept in the
+    /// value or opaque type storage as well, this prevents us from accidentally
+    /// relying on it in the future.
+    ///
+    /// We want to keep the option of canonicalizing `'static` to an existential
+    /// variable in the future by changing the way we detect global where-bounds.
+    pub fn canonicalize_input<P: TypeFoldable<I>>(
+        delegate: &'a D,
+        variables: &'a mut Vec<I::GenericArg>,
+        input: QueryInput<I, P>,
+    ) -> ty::Canonical<I, QueryInput<I, P>> {
+        // First canonicalize the `param_env` while keeping `'static`
+        let mut env_canonicalizer = Canonicalizer {
+            delegate,
+            canonicalize_mode: CanonicalizeMode::Input { keep_static: true },
+
+            variables,
+            variable_lookup_table: Default::default(),
+            primitive_var_infos: Vec::new(),
+            binder_index: ty::INNERMOST,
+
+            cache: Default::default(),
+        };
+        let param_env = input.goal.param_env.fold_with(&mut env_canonicalizer);
+        debug_assert_eq!(env_canonicalizer.binder_index, ty::INNERMOST);
+        // Then canonicalize the rest of the input without keeping `'static`
+        // while *mostly* reusing the canonicalizer from above.
+        let mut rest_canonicalizer = Canonicalizer {
+            delegate,
+            canonicalize_mode: CanonicalizeMode::Input { keep_static: false },
+
+            variables: env_canonicalizer.variables,
+            // We're able to reuse the `variable_lookup_table` as whether or not
+            // it already contains an entry for `'static` does not matter.
+            variable_lookup_table: env_canonicalizer.variable_lookup_table,
+            primitive_var_infos: env_canonicalizer.primitive_var_infos,
+            binder_index: ty::INNERMOST,
 
+            // We do not reuse the cache as it may contain entries whose canonicalized
+            // value contains `'static`. While we could alternatively handle this by
+            // checking for `'static` when using cached entries, this does not
+            // feel worth the effort. I do not expect that a `ParamEnv` will ever
+            // contain large enough types for caching to be necessary.
+            cache: Default::default(),
+        };
+
+        let predicate = input.goal.predicate.fold_with(&mut rest_canonicalizer);
+        let goal = Goal { param_env, predicate };
+        let predefined_opaques_in_body =
+            input.predefined_opaques_in_body.fold_with(&mut rest_canonicalizer);
+        let value = QueryInput { goal, predefined_opaques_in_body };
+
+        assert!(!value.has_infer(), "unexpected infer in {value:?}");
+        assert!(!value.has_placeholders(), "unexpected placeholders in {value:?}");
+        let (max_universe, variables) = rest_canonicalizer.finalize();
         Canonical { max_universe, variables, value }
     }
 
@@ -126,7 +188,7 @@ impl<'a, D: SolverDelegate<Interner = I>, I: Interner> Canonicalizer<'a, D, I> {
             // all information which should not matter for the solver.
             //
             // For this we compress universes as much as possible.
-            CanonicalizeMode::Input => {}
+            CanonicalizeMode::Input { .. } => {}
             // When canonicalizing a response we map a universes already entered
             // by the caller to the root universe and only return useful universe
             // information for placeholders and inference variables created inside
@@ -290,17 +352,15 @@ impl<'a, D: SolverDelegate<Interner = I>, I: Interner> Canonicalizer<'a, D, I> {
                 }
             },
             ty::Placeholder(placeholder) => match self.canonicalize_mode {
-                CanonicalizeMode::Input => CanonicalVarKind::PlaceholderTy(PlaceholderLike::new(
-                    placeholder.universe(),
-                    self.variables.len().into(),
-                )),
+                CanonicalizeMode::Input { .. } => CanonicalVarKind::PlaceholderTy(
+                    PlaceholderLike::new(placeholder.universe(), self.variables.len().into()),
+                ),
                 CanonicalizeMode::Response { .. } => CanonicalVarKind::PlaceholderTy(placeholder),
             },
             ty::Param(_) => match self.canonicalize_mode {
-                CanonicalizeMode::Input => CanonicalVarKind::PlaceholderTy(PlaceholderLike::new(
-                    ty::UniverseIndex::ROOT,
-                    self.variables.len().into(),
-                )),
+                CanonicalizeMode::Input { .. } => CanonicalVarKind::PlaceholderTy(
+                    PlaceholderLike::new(ty::UniverseIndex::ROOT, self.variables.len().into()),
+                ),
                 CanonicalizeMode::Response { .. } => panic!("param ty in response: {t:?}"),
             },
             ty::Bool
@@ -357,21 +417,30 @@ impl<D: SolverDelegate<Interner = I>, I: Interner> TypeFolder<I> for Canonicaliz
         let kind = match r.kind() {
             ty::ReBound(..) => return r,
 
-            // We may encounter `ReStatic` in item signatures or the hidden type
-            // of an opaque. `ReErased` should only be encountered in the hidden
+            // We don't canonicalize `ReStatic` in the `param_env` as we use it
+            // when checking whether a `ParamEnv` candidate is global.
+            ty::ReStatic => match self.canonicalize_mode {
+                CanonicalizeMode::Input { keep_static: false } => {
+                    CanonicalVarKind::Region(ty::UniverseIndex::ROOT)
+                }
+                CanonicalizeMode::Input { keep_static: true }
+                | CanonicalizeMode::Response { .. } => return r,
+            },
+
+            // `ReErased` should only be encountered in the hidden
             // type of an opaque for regions that are ignored for the purposes of
             // captures.
             //
             // FIXME: We should investigate the perf implications of not uniquifying
             // `ReErased`. We may be able to short-circuit registering region
             // obligations if we encounter a `ReErased` on one side, for example.
-            ty::ReStatic | ty::ReErased | ty::ReError(_) => match self.canonicalize_mode {
-                CanonicalizeMode::Input => CanonicalVarKind::Region(ty::UniverseIndex::ROOT),
+            ty::ReErased | ty::ReError(_) => match self.canonicalize_mode {
+                CanonicalizeMode::Input { .. } => CanonicalVarKind::Region(ty::UniverseIndex::ROOT),
                 CanonicalizeMode::Response { .. } => return r,
             },
 
             ty::ReEarlyParam(_) | ty::ReLateParam(_) => match self.canonicalize_mode {
-                CanonicalizeMode::Input => CanonicalVarKind::Region(ty::UniverseIndex::ROOT),
+                CanonicalizeMode::Input { .. } => CanonicalVarKind::Region(ty::UniverseIndex::ROOT),
                 CanonicalizeMode::Response { .. } => {
                     panic!("unexpected region in response: {r:?}")
                 }
@@ -379,7 +448,7 @@ impl<D: SolverDelegate<Interner = I>, I: Interner> TypeFolder<I> for Canonicaliz
 
             ty::RePlaceholder(placeholder) => match self.canonicalize_mode {
                 // We canonicalize placeholder regions as existentials in query inputs.
-                CanonicalizeMode::Input => CanonicalVarKind::Region(ty::UniverseIndex::ROOT),
+                CanonicalizeMode::Input { .. } => CanonicalVarKind::Region(ty::UniverseIndex::ROOT),
                 CanonicalizeMode::Response { max_input_universe } => {
                     // If we have a placeholder region inside of a query, it must be from
                     // a new universe.
@@ -397,7 +466,9 @@ impl<D: SolverDelegate<Interner = I>, I: Interner> TypeFolder<I> for Canonicaliz
                     "region vid should have been resolved fully before canonicalization"
                 );
                 match self.canonicalize_mode {
-                    CanonicalizeMode::Input => CanonicalVarKind::Region(ty::UniverseIndex::ROOT),
+                    CanonicalizeMode::Input { keep_static: _ } => {
+                        CanonicalVarKind::Region(ty::UniverseIndex::ROOT)
+                    }
                     CanonicalizeMode::Response { .. } => {
                         CanonicalVarKind::Region(self.delegate.universe_of_lt(vid).unwrap())
                     }
@@ -434,7 +505,7 @@ impl<D: SolverDelegate<Interner = I>, I: Interner> TypeFolder<I> for Canonicaliz
                 ty::InferConst::Fresh(_) => todo!(),
             },
             ty::ConstKind::Placeholder(placeholder) => match self.canonicalize_mode {
-                CanonicalizeMode::Input => CanonicalVarKind::PlaceholderConst(
+                CanonicalizeMode::Input { .. } => CanonicalVarKind::PlaceholderConst(
                     PlaceholderLike::new(placeholder.universe(), self.variables.len().into()),
                 ),
                 CanonicalizeMode::Response { .. } => {
@@ -442,7 +513,7 @@ impl<D: SolverDelegate<Interner = I>, I: Interner> TypeFolder<I> for Canonicaliz
                 }
             },
             ty::ConstKind::Param(_) => match self.canonicalize_mode {
-                CanonicalizeMode::Input => CanonicalVarKind::PlaceholderConst(
+                CanonicalizeMode::Input { .. } => CanonicalVarKind::PlaceholderConst(
                     PlaceholderLike::new(ty::UniverseIndex::ROOT, self.variables.len().into()),
                 ),
                 CanonicalizeMode::Response { .. } => panic!("param ty in response: {c:?}"),
diff --git a/compiler/rustc_next_trait_solver/src/solve/assembly/mod.rs b/compiler/rustc_next_trait_solver/src/solve/assembly/mod.rs
index 198ccb000f3..02f6439b77f 100644
--- a/compiler/rustc_next_trait_solver/src/solve/assembly/mod.rs
+++ b/compiler/rustc_next_trait_solver/src/solve/assembly/mod.rs
@@ -11,6 +11,7 @@ use rustc_type_ir::visit::TypeVisitableExt as _;
 use rustc_type_ir::{self as ty, Interner, TypingMode, Upcast as _, elaborate};
 use tracing::{debug, instrument};
 
+use super::trait_goals::TraitGoalProvenVia;
 use crate::delegate::SolverDelegate;
 use crate::solve::inspect::ProbeKind;
 use crate::solve::{
@@ -337,15 +338,6 @@ where
 
         self.assemble_param_env_candidates(goal, &mut candidates);
 
-        match self.typing_mode() {
-            TypingMode::Coherence => {}
-            TypingMode::Analysis { .. }
-            | TypingMode::PostBorrowckAnalysis { .. }
-            | TypingMode::PostAnalysis => {
-                self.discard_impls_shadowed_by_env(goal, &mut candidates);
-            }
-        }
-
         candidates
     }
 
@@ -500,7 +492,7 @@ where
         goal: Goal<I, G>,
         candidates: &mut Vec<Candidate<I>>,
     ) {
-        for (i, assumption) in goal.param_env.caller_bounds().into_iter().enumerate() {
+        for (i, assumption) in goal.param_env.caller_bounds().iter().enumerate() {
             candidates.extend(G::probe_and_consider_implied_clause(
                 self,
                 CandidateSource::ParamEnv(i),
@@ -733,72 +725,64 @@ where
         })
     }
 
-    /// If there's a where-bound for the current goal, do not use any impl candidates
-    /// to prove the current goal. Most importantly, if there is a where-bound which does
-    /// not specify any associated types, we do not allow normalizing the associated type
-    /// by using an impl, even if it would apply.
+    /// We sadly can't simply take all possible candidates for normalization goals
+    /// and check whether they result in the same constraints. We want to make sure
+    /// that trying to normalize an alias doesn't result in constraints which aren't
+    /// otherwise required.
+    ///
+    /// Most notably, when proving a trait goal by via a where-bound, we should not
+    /// normalize via impls which have stricter region constraints than the where-bound:
+    ///
+    /// ```rust
+    /// trait Trait<'a> {
+    ///     type Assoc;
+    /// }
+    ///
+    /// impl<'a, T: 'a> Trait<'a> for T {
+    ///     type Assoc = u32;
+    /// }
+    ///
+    /// fn with_bound<'a, T: Trait<'a>>(_value: T::Assoc) {}
+    /// ```
     ///
-    ///  <https://github.com/rust-lang/trait-system-refactor-initiative/issues/76>
-    // FIXME(@lcnr): The current structure here makes me unhappy and feels ugly. idk how
-    // to improve this however. However, this should make it fairly straightforward to refine
-    // the filtering going forward, so it seems alright-ish for now.
-    #[instrument(level = "debug", skip(self, goal))]
-    fn discard_impls_shadowed_by_env<G: GoalKind<D>>(
+    /// The where-bound of `with_bound` doesn't specify the associated type, so we would
+    /// only be able to normalize `<T as Trait<'a>>::Assoc` by using the impl. This impl
+    /// adds a `T: 'a` bound however, which would result in a region error. Given that the
+    /// user explicitly wrote that `T: Trait<'a>` holds, this is undesirable and we instead
+    /// treat the alias as rigid.
+    ///
+    /// See trait-system-refactor-initiative#124 for more details.
+    #[instrument(level = "debug", skip(self), ret)]
+    pub(super) fn merge_candidates(
         &mut self,
-        goal: Goal<I, G>,
-        candidates: &mut Vec<Candidate<I>>,
-    ) {
-        let cx = self.cx();
-        let trait_goal: Goal<I, ty::TraitPredicate<I>> =
-            goal.with(cx, goal.predicate.trait_ref(cx));
-
-        let mut trait_candidates_from_env = vec![];
-        self.probe(|_| ProbeKind::ShadowedEnvProbing).enter(|ecx| {
-            ecx.assemble_param_env_candidates(trait_goal, &mut trait_candidates_from_env);
-            ecx.assemble_alias_bound_candidates(trait_goal, &mut trait_candidates_from_env);
-        });
+        proven_via: Option<TraitGoalProvenVia>,
+        candidates: Vec<Candidate<I>>,
+    ) -> QueryResult<I> {
+        let Some(proven_via) = proven_via else {
+            // We don't care about overflow. If proving the trait goal overflowed, then
+            // it's enough to report an overflow error for that, we don't also have to
+            // overflow during normalization.
+            return Ok(self.make_ambiguous_response_no_constraints(MaybeCause::Ambiguity));
+        };
 
-        if !trait_candidates_from_env.is_empty() {
-            let trait_env_result = self.merge_candidates(trait_candidates_from_env);
-            match trait_env_result.unwrap().value.certainty {
-                // If proving the trait goal succeeds by using the env,
-                // we freely drop all impl candidates.
-                //
-                // FIXME(@lcnr): It feels like this could easily hide
-                // a forced ambiguity candidate added earlier.
-                // This feels dangerous.
-                Certainty::Yes => {
-                    candidates.retain(|c| match c.source {
-                        CandidateSource::Impl(_) | CandidateSource::BuiltinImpl(_) => {
-                            debug!(?c, "discard impl candidate");
-                            false
-                        }
-                        CandidateSource::ParamEnv(_) | CandidateSource::AliasBound => true,
-                        CandidateSource::CoherenceUnknowable => panic!("uh oh"),
-                    });
-                }
-                // If it is still ambiguous we instead just force the whole goal
-                // to be ambig and wait for inference constraints. See
-                // tests/ui/traits/next-solver/env-shadows-impls/ambig-env-no-shadow.rs
-                Certainty::Maybe(cause) => {
-                    debug!(?cause, "force ambiguity");
-                    *candidates = self.forced_ambiguity(cause).into_iter().collect();
-                }
-            }
-        }
-    }
+        let responses: Vec<_> = match proven_via {
+            // Even when a trait bound has been proven using a where-bound, we
+            // still need to consider alias-bounds for normalization, see
+            // tests/ui/next-solver/alias-bound-shadowed-by-env.rs.
+            //
+            // FIXME(const_trait_impl): should this behavior also be used by
+            // constness checking. Doing so is *at least theoretically* breaking,
+            // see github.com/rust-lang/rust/issues/133044#issuecomment-2500709754
+            TraitGoalProvenVia::ParamEnv | TraitGoalProvenVia::AliasBound => candidates
+                .iter()
+                .filter(|c| {
+                    matches!(c.source, CandidateSource::AliasBound | CandidateSource::ParamEnv(_))
+                })
+                .map(|c| c.result)
+                .collect(),
+            TraitGoalProvenVia::Misc => candidates.iter().map(|c| c.result).collect(),
+        };
 
-    /// If there are multiple ways to prove a trait or projection goal, we have
-    /// to somehow try to merge the candidates into one. If that fails, we return
-    /// ambiguity.
-    #[instrument(level = "debug", skip(self), ret)]
-    pub(super) fn merge_candidates(&mut self, candidates: Vec<Candidate<I>>) -> QueryResult<I> {
-        // First try merging all candidates. This is complete and fully sound.
-        let responses = candidates.iter().map(|c| c.result).collect::<Vec<_>>();
-        if let Some(result) = self.try_merge_responses(&responses) {
-            return Ok(result);
-        } else {
-            self.flounder(&responses)
-        }
+        self.try_merge_responses(&responses).map_or_else(|| self.flounder(&responses), Ok)
     }
 }
diff --git a/compiler/rustc_next_trait_solver/src/solve/effect_goals.rs b/compiler/rustc_next_trait_solver/src/solve/effect_goals.rs
index 81b5199002b..ce7552e30f0 100644
--- a/compiler/rustc_next_trait_solver/src/solve/effect_goals.rs
+++ b/compiler/rustc_next_trait_solver/src/solve/effect_goals.rs
@@ -4,6 +4,7 @@
 use rustc_type_ir::fast_reject::DeepRejectCtxt;
 use rustc_type_ir::inherent::*;
 use rustc_type_ir::lang_items::TraitSolverLangItem;
+use rustc_type_ir::solve::inspect::ProbeKind;
 use rustc_type_ir::{self as ty, Interner, elaborate};
 use tracing::instrument;
 
@@ -391,6 +392,11 @@ where
         goal: Goal<I, ty::HostEffectPredicate<I>>,
     ) -> QueryResult<I> {
         let candidates = self.assemble_and_evaluate_candidates(goal);
-        self.merge_candidates(candidates)
+        let (_, proven_via) = self.probe(|_| ProbeKind::ShadowedEnvProbing).enter(|ecx| {
+            let trait_goal: Goal<I, ty::TraitPredicate<I>> =
+                goal.with(ecx.cx(), goal.predicate.trait_ref);
+            ecx.compute_trait_goal(trait_goal)
+        })?;
+        self.merge_candidates(proven_via, candidates)
     }
 }
diff --git a/compiler/rustc_next_trait_solver/src/solve/eval_ctxt/canonical.rs b/compiler/rustc_next_trait_solver/src/solve/eval_ctxt/canonical.rs
index a143af13688..e99cd3d2727 100644
--- a/compiler/rustc_next_trait_solver/src/solve/eval_ctxt/canonical.rs
+++ b/compiler/rustc_next_trait_solver/src/solve/eval_ctxt/canonical.rs
@@ -18,7 +18,7 @@ use rustc_type_ir::relate::solver_relating::RelateExt;
 use rustc_type_ir::{self as ty, Canonical, CanonicalVarValues, InferCtxtLike, Interner};
 use tracing::{debug, instrument, trace};
 
-use crate::canonicalizer::{CanonicalizeMode, Canonicalizer};
+use crate::canonicalizer::Canonicalizer;
 use crate::delegate::SolverDelegate;
 use crate::resolve::EagerResolver;
 use crate::solve::eval_ctxt::NestedGoals;
@@ -60,17 +60,13 @@ where
             (goal, opaque_types).fold_with(&mut EagerResolver::new(self.delegate));
 
         let mut orig_values = Default::default();
-        let canonical = Canonicalizer::canonicalize(
-            self.delegate,
-            CanonicalizeMode::Input,
-            &mut orig_values,
-            QueryInput {
+        let canonical =
+            Canonicalizer::canonicalize_input(self.delegate, &mut orig_values, QueryInput {
                 goal,
                 predefined_opaques_in_body: self
                     .cx()
                     .mk_predefined_opaques_in_body(PredefinedOpaquesData { opaque_types }),
-            },
-        );
+            });
         let query_input = ty::CanonicalQueryInput { canonical, typing_mode: self.typing_mode() };
         (orig_values, query_input)
     }
@@ -148,9 +144,9 @@ where
             .region_constraints
             .retain(|outlives| outlives.0.as_region().map_or(true, |re| re != outlives.1));
 
-        let canonical = Canonicalizer::canonicalize(
+        let canonical = Canonicalizer::canonicalize_response(
             self.delegate,
-            CanonicalizeMode::Response { max_input_universe: self.max_input_universe },
+            self.max_input_universe,
             &mut Default::default(),
             Response {
                 var_values,
@@ -428,12 +424,7 @@ where
     let var_values = CanonicalVarValues { var_values: delegate.cx().mk_args(var_values) };
     let state = inspect::State { var_values, data };
     let state = state.fold_with(&mut EagerResolver::new(delegate));
-    Canonicalizer::canonicalize(
-        delegate,
-        CanonicalizeMode::Response { max_input_universe },
-        &mut vec![],
-        state,
-    )
+    Canonicalizer::canonicalize_response(delegate, max_input_universe, &mut vec![], state)
 }
 
 // FIXME: needs to be pub to be accessed by downstream
diff --git a/compiler/rustc_next_trait_solver/src/solve/eval_ctxt/mod.rs b/compiler/rustc_next_trait_solver/src/solve/eval_ctxt/mod.rs
index 70ceb22bfea..8c74490e0e0 100644
--- a/compiler/rustc_next_trait_solver/src/solve/eval_ctxt/mod.rs
+++ b/compiler/rustc_next_trait_solver/src/solve/eval_ctxt/mod.rs
@@ -440,7 +440,7 @@ where
         if let Some(kind) = kind.no_bound_vars() {
             match kind {
                 ty::PredicateKind::Clause(ty::ClauseKind::Trait(predicate)) => {
-                    self.compute_trait_goal(Goal { param_env, predicate })
+                    self.compute_trait_goal(Goal { param_env, predicate }).map(|(r, _via)| r)
                 }
                 ty::PredicateKind::Clause(ty::ClauseKind::HostEffect(predicate)) => {
                     self.compute_host_effect_goal(Goal { param_env, predicate })
diff --git a/compiler/rustc_next_trait_solver/src/solve/mod.rs b/compiler/rustc_next_trait_solver/src/solve/mod.rs
index ebf1013db1e..37678bfd880 100644
--- a/compiler/rustc_next_trait_solver/src/solve/mod.rs
+++ b/compiler/rustc_next_trait_solver/src/solve/mod.rs
@@ -243,22 +243,27 @@ where
             .copied()
     }
 
+    fn bail_with_ambiguity(&mut self, responses: &[CanonicalResponse<I>]) -> CanonicalResponse<I> {
+        debug_assert!(!responses.is_empty());
+        if let Certainty::Maybe(maybe_cause) =
+            responses.iter().fold(Certainty::AMBIGUOUS, |certainty, response| {
+                certainty.unify_with(response.value.certainty)
+            })
+        {
+            self.make_ambiguous_response_no_constraints(maybe_cause)
+        } else {
+            panic!("expected flounder response to be ambiguous")
+        }
+    }
+
     /// If we fail to merge responses we flounder and return overflow or ambiguity.
     #[instrument(level = "trace", skip(self), ret)]
     fn flounder(&mut self, responses: &[CanonicalResponse<I>]) -> QueryResult<I> {
         if responses.is_empty() {
             return Err(NoSolution);
+        } else {
+            Ok(self.bail_with_ambiguity(responses))
         }
-
-        let Certainty::Maybe(maybe_cause) =
-            responses.iter().fold(Certainty::AMBIGUOUS, |certainty, response| {
-                certainty.unify_with(response.value.certainty)
-            })
-        else {
-            panic!("expected flounder response to be ambiguous")
-        };
-
-        Ok(self.make_ambiguous_response_no_constraints(maybe_cause))
     }
 
     /// Normalize a type for when it is structurally matched on.
diff --git a/compiler/rustc_next_trait_solver/src/solve/normalizes_to/mod.rs b/compiler/rustc_next_trait_solver/src/solve/normalizes_to/mod.rs
index 63dbee2640b..b8867192225 100644
--- a/compiler/rustc_next_trait_solver/src/solve/normalizes_to/mod.rs
+++ b/compiler/rustc_next_trait_solver/src/solve/normalizes_to/mod.rs
@@ -88,10 +88,17 @@ where
     /// returns `NoSolution`.
     #[instrument(level = "trace", skip(self), ret)]
     fn normalize_at_least_one_step(&mut self, goal: Goal<I, NormalizesTo<I>>) -> QueryResult<I> {
-        match goal.predicate.alias.kind(self.cx()) {
+        let cx = self.cx();
+        match goal.predicate.alias.kind(cx) {
             ty::AliasTermKind::ProjectionTy | ty::AliasTermKind::ProjectionConst => {
                 let candidates = self.assemble_and_evaluate_candidates(goal);
-                self.merge_candidates(candidates)
+                let (_, proven_via) =
+                    self.probe(|_| ProbeKind::ShadowedEnvProbing).enter(|ecx| {
+                        let trait_goal: Goal<I, ty::TraitPredicate<I>> =
+                            goal.with(cx, goal.predicate.alias.trait_ref(cx));
+                        ecx.compute_trait_goal(trait_goal)
+                    })?;
+                self.merge_candidates(proven_via, candidates)
             }
             ty::AliasTermKind::InherentTy => self.normalize_inherent_associated_type(goal),
             ty::AliasTermKind::OpaqueTy => self.normalize_opaque_type(goal),
diff --git a/compiler/rustc_next_trait_solver/src/solve/trait_goals.rs b/compiler/rustc_next_trait_solver/src/solve/trait_goals.rs
index 12df35d30b8..886cdec0345 100644
--- a/compiler/rustc_next_trait_solver/src/solve/trait_goals.rs
+++ b/compiler/rustc_next_trait_solver/src/solve/trait_goals.rs
@@ -5,6 +5,7 @@ use rustc_type_ir::data_structures::IndexSet;
 use rustc_type_ir::fast_reject::DeepRejectCtxt;
 use rustc_type_ir::inherent::*;
 use rustc_type_ir::lang_items::TraitSolverLangItem;
+use rustc_type_ir::solve::CanonicalResponse;
 use rustc_type_ir::visit::TypeVisitableExt as _;
 use rustc_type_ir::{self as ty, Interner, TraitPredicate, TypingMode, Upcast as _, elaborate};
 use tracing::{instrument, trace};
@@ -1147,13 +1148,101 @@ where
             ecx.evaluate_added_goals_and_make_canonical_response(Certainty::Yes)
         })
     }
+}
+
+/// How we've proven this trait goal.
+///
+/// This is used by `NormalizesTo` goals to only normalize
+/// by using the same 'kind of candidate' we've used to prove
+/// its corresponding trait goal. Most notably, we do not
+/// normalize by using an impl if the trait goal has been
+/// proven via a `ParamEnv` candidate.
+///
+/// This is necessary to avoid unnecessary region constraints,
+/// see trait-system-refactor-initiative#125 for more details.
+#[derive(Debug, Clone, Copy)]
+pub(super) enum TraitGoalProvenVia {
+    /// We've proven the trait goal by something which is
+    /// is not a non-global where-bound or an alias-bound.
+    ///
+    /// This means we don't disable any candidates during
+    /// normalization.
+    Misc,
+    ParamEnv,
+    AliasBound,
+}
+
+impl<D, I> EvalCtxt<'_, D>
+where
+    D: SolverDelegate<Interner = I>,
+    I: Interner,
+{
+    pub(super) fn merge_trait_candidates(
+        &mut self,
+        goal: Goal<I, TraitPredicate<I>>,
+        candidates: Vec<Candidate<I>>,
+    ) -> Result<(CanonicalResponse<I>, Option<TraitGoalProvenVia>), NoSolution> {
+        if let TypingMode::Coherence = self.typing_mode() {
+            let all_candidates: Vec<_> = candidates.into_iter().map(|c| c.result).collect();
+            return if let Some(response) = self.try_merge_responses(&all_candidates) {
+                Ok((response, Some(TraitGoalProvenVia::Misc)))
+            } else {
+                self.flounder(&all_candidates).map(|r| (r, None))
+            };
+        }
+
+        // FIXME: prefer trivial builtin impls
+
+        // If there are non-global where-bounds, prefer where-bounds
+        // (including global ones) over everything else.
+        let has_non_global_where_bounds = candidates.iter().any(|c| match c.source {
+            CandidateSource::ParamEnv(idx) => {
+                let where_bound = goal.param_env.caller_bounds().get(idx);
+                where_bound.has_bound_vars() || !where_bound.is_global()
+            }
+            _ => false,
+        });
+        if has_non_global_where_bounds {
+            let where_bounds: Vec<_> = candidates
+                .iter()
+                .filter(|c| matches!(c.source, CandidateSource::ParamEnv(_)))
+                .map(|c| c.result)
+                .collect();
+
+            return if let Some(response) = self.try_merge_responses(&where_bounds) {
+                Ok((response, Some(TraitGoalProvenVia::ParamEnv)))
+            } else {
+                Ok((self.bail_with_ambiguity(&where_bounds), None))
+            };
+        }
+
+        if candidates.iter().any(|c| matches!(c.source, CandidateSource::AliasBound)) {
+            let alias_bounds: Vec<_> = candidates
+                .iter()
+                .filter(|c| matches!(c.source, CandidateSource::AliasBound))
+                .map(|c| c.result)
+                .collect();
+            return if let Some(response) = self.try_merge_responses(&alias_bounds) {
+                Ok((response, Some(TraitGoalProvenVia::AliasBound)))
+            } else {
+                Ok((self.bail_with_ambiguity(&alias_bounds), None))
+            };
+        }
+
+        let all_candidates: Vec<_> = candidates.into_iter().map(|c| c.result).collect();
+        if let Some(response) = self.try_merge_responses(&all_candidates) {
+            Ok((response, Some(TraitGoalProvenVia::Misc)))
+        } else {
+            self.flounder(&all_candidates).map(|r| (r, None))
+        }
+    }
 
     #[instrument(level = "trace", skip(self))]
     pub(super) fn compute_trait_goal(
         &mut self,
         goal: Goal<I, TraitPredicate<I>>,
-    ) -> QueryResult<I> {
+    ) -> Result<(CanonicalResponse<I>, Option<TraitGoalProvenVia>), NoSolution> {
         let candidates = self.assemble_and_evaluate_candidates(goal);
-        self.merge_candidates(candidates)
+        self.merge_trait_candidates(goal, candidates)
     }
 }
diff --git a/compiler/rustc_passes/messages.ftl b/compiler/rustc_passes/messages.ftl
index fd133ba878e..9cc94b75624 100644
--- a/compiler/rustc_passes/messages.ftl
+++ b/compiler/rustc_passes/messages.ftl
@@ -357,6 +357,9 @@ passes_ignored_derived_impls =
 passes_implied_feature_not_exist =
     feature `{$implied_by}` implying `{$feature}` does not exist
 
+passes_incorrect_do_not_recommend_args =
+    `#[diagnostic::do_not_recommend]` does not expect any arguments
+
 passes_incorrect_do_not_recommend_location =
     `#[diagnostic::do_not_recommend]` can only be placed on trait implementations
 
diff --git a/compiler/rustc_passes/src/check_attr.rs b/compiler/rustc_passes/src/check_attr.rs
index ce7947ad3ec..2310dd9dc72 100644
--- a/compiler/rustc_passes/src/check_attr.rs
+++ b/compiler/rustc_passes/src/check_attr.rs
@@ -115,7 +115,7 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
         for attr in attrs {
             match attr.path().as_slice() {
                 [sym::diagnostic, sym::do_not_recommend, ..] => {
-                    self.check_do_not_recommend(attr.span, hir_id, target)
+                    self.check_do_not_recommend(attr.span, hir_id, target, attr, item)
                 }
                 [sym::diagnostic, sym::on_unimplemented, ..] => {
                     self.check_diagnostic_on_unimplemented(attr.span, hir_id, target)
@@ -348,8 +348,21 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
     }
 
     /// Checks if `#[diagnostic::do_not_recommend]` is applied on a trait impl.
-    fn check_do_not_recommend(&self, attr_span: Span, hir_id: HirId, target: Target) {
-        if !matches!(target, Target::Impl) {
+    fn check_do_not_recommend(
+        &self,
+        attr_span: Span,
+        hir_id: HirId,
+        target: Target,
+        attr: &Attribute,
+        item: Option<ItemLike<'_>>,
+    ) {
+        if !matches!(target, Target::Impl)
+            || matches!(
+                item,
+                Some(ItemLike::Item(hir::Item {  kind: hir::ItemKind::Impl(_impl),.. }))
+                    if _impl.of_trait.is_none()
+            )
+        {
             self.tcx.emit_node_span_lint(
                 UNKNOWN_OR_MALFORMED_DIAGNOSTIC_ATTRIBUTES,
                 hir_id,
@@ -357,6 +370,14 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
                 errors::IncorrectDoNotRecommendLocation,
             );
         }
+        if !attr.is_word() {
+            self.tcx.emit_node_span_lint(
+                UNKNOWN_OR_MALFORMED_DIAGNOSTIC_ATTRIBUTES,
+                hir_id,
+                attr_span,
+                errors::DoNotRecommendDoesNotExpectArgs,
+            );
+        }
     }
 
     /// Checks if `#[diagnostic::on_unimplemented]` is applied to a trait definition
diff --git a/compiler/rustc_passes/src/errors.rs b/compiler/rustc_passes/src/errors.rs
index f71d5284052..5e7bfa5e3bb 100644
--- a/compiler/rustc_passes/src/errors.rs
+++ b/compiler/rustc_passes/src/errors.rs
@@ -20,6 +20,10 @@ use crate::lang_items::Duplicate;
 #[diag(passes_incorrect_do_not_recommend_location)]
 pub(crate) struct IncorrectDoNotRecommendLocation;
 
+#[derive(LintDiagnostic)]
+#[diag(passes_incorrect_do_not_recommend_args)]
+pub(crate) struct DoNotRecommendDoesNotExpectArgs;
+
 #[derive(Diagnostic)]
 #[diag(passes_autodiff_attr)]
 pub(crate) struct AutoDiffAttr {
diff --git a/compiler/rustc_resolve/src/late.rs b/compiler/rustc_resolve/src/late.rs
index a48a2865228..7324d3fe786 100644
--- a/compiler/rustc_resolve/src/late.rs
+++ b/compiler/rustc_resolve/src/late.rs
@@ -4325,7 +4325,7 @@ impl<'a, 'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'a, 'ast, 'ra, 'tcx> {
 
     #[inline]
     /// If we're actually rustdoc then avoid giving a name resolution error for `cfg()` items or
-    // an invalid `use foo::*;` was found, which can cause unbounded ammounts of "item not found"
+    // an invalid `use foo::*;` was found, which can cause unbounded amounts of "item not found"
     // errors. We silence them all.
     fn should_report_errs(&self) -> bool {
         !(self.r.tcx.sess.opts.actually_rustdoc && self.in_func_body)
diff --git a/compiler/rustc_resolve/src/macros.rs b/compiler/rustc_resolve/src/macros.rs
index edee19c280a..b24e343c58d 100644
--- a/compiler/rustc_resolve/src/macros.rs
+++ b/compiler/rustc_resolve/src/macros.rs
@@ -689,8 +689,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
             && let [namespace, attribute, ..] = &*path.segments
             && namespace.ident.name == sym::diagnostic
             && !(attribute.ident.name == sym::on_unimplemented
-                || (attribute.ident.name == sym::do_not_recommend
-                    && self.tcx.features().do_not_recommend()))
+                || attribute.ident.name == sym::do_not_recommend)
         {
             let distance =
                 edit_distance(attribute.ident.name.as_str(), sym::on_unimplemented.as_str(), 5);
diff --git a/compiler/rustc_trait_selection/src/traits/mod.rs b/compiler/rustc_trait_selection/src/traits/mod.rs
index 069d42d4018..1dcd0d0dfb8 100644
--- a/compiler/rustc_trait_selection/src/traits/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/mod.rs
@@ -599,7 +599,7 @@ pub fn try_evaluate_const<'tcx>(
                 // even though it is not something we should ever actually encounter.
                 //
                 // Array repeat expr counts are allowed to syntactically use generic parameters
-                // but must not actually depend on them in order to evalaute succesfully. This means
+                // but must not actually depend on them in order to evalaute successfully. This means
                 // that it is actually fine to evalaute them in their own environment rather than with
                 // the actually provided generic arguments.
                 tcx.dcx().delayed_bug(
diff --git a/compiler/rustc_type_ir/src/inherent.rs b/compiler/rustc_type_ir/src/inherent.rs
index f45c94127bd..2db40accda3 100644
--- a/compiler/rustc_type_ir/src/inherent.rs
+++ b/compiler/rustc_type_ir/src/inherent.rs
@@ -543,7 +543,7 @@ pub trait AdtDef<I: Interner>: Copy + Debug + Hash + Eq {
 }
 
 pub trait ParamEnv<I: Interner>: Copy + Debug + Hash + Eq + TypeFoldable<I> {
-    fn caller_bounds(self) -> impl IntoIterator<Item = I::Clause>;
+    fn caller_bounds(self) -> impl SliceLike<Item = I::Clause>;
 }
 
 pub trait Features<I: Interner>: Copy {
diff --git a/library/core/src/lib.rs b/library/core/src/lib.rs
index 922866f95dc..18bd9bb8118 100644
--- a/library/core/src/lib.rs
+++ b/library/core/src/lib.rs
@@ -108,12 +108,12 @@
 // Library features:
 // tidy-alphabetical-start
 #![cfg_attr(bootstrap, feature(coverage_attribute))]
+#![cfg_attr(bootstrap, feature(do_not_recommend))]
 #![feature(array_ptr_get)]
 #![feature(asm_experimental_arch)]
 #![feature(const_eval_select)]
 #![feature(const_typed_swap)]
 #![feature(core_intrinsics)]
-#![feature(do_not_recommend)]
 #![feature(internal_impls_macro)]
 #![feature(ip)]
 #![feature(is_ascii_octdigit)]
diff --git a/library/core/src/ptr/mod.rs b/library/core/src/ptr/mod.rs
index 51ab2054b3b..1423e7ea8d1 100644
--- a/library/core/src/ptr/mod.rs
+++ b/library/core/src/ptr/mod.rs
@@ -84,7 +84,7 @@
 // ^ we use this term instead of saying that the produced reference must
 // be valid, as the validity of a reference is easily confused for the
 // validity of the thing it refers to, and while the two concepts are
-// closly related, they are not identical.
+// closely related, they are not identical.
 //!
 //! These rules apply even if the result is unused!
 //! (The part about being initialized is not yet fully decided, but until
diff --git a/src/doc/book b/src/doc/book
-Subproject 9900d976bbfecf4e8124da54351a9ad85ee3c7f
+Subproject ad2011d3bcad9f152d034faf7635c22506839d5
diff --git a/src/doc/edition-guide b/src/doc/edition-guide
-Subproject 128669297c8a7fdf771042eaec18b8adfaeaf0c
+Subproject bc4ce51e1d4dacb9350a92e95f6159a42de2f8c
diff --git a/src/doc/nomicon b/src/doc/nomicon
-Subproject 0674321898cd454764ab69702819d39a919afd6
+Subproject 97e84a38c94bf9362b11284c20b2cb4adaa1e86
diff --git a/src/doc/reference b/src/doc/reference
-Subproject ede56d1bbe132bac476b5029cd6d7508ca9572e
+Subproject 9f41bc11342d46544ae0732caf14ec0bcaf2737
diff --git a/src/doc/rust-by-example b/src/doc/rust-by-example
-Subproject e1d1f2cdcee4d52b9a01ff7c448be4372a377b7
+Subproject 76406337f4131253443aea0ed7e7f451b464117
diff --git a/src/doc/rustc-dev-guide b/src/doc/rustc-dev-guide
-Subproject b21d99b770f9aceb0810c843847c52f86f45d2e
+Subproject 7f7ba48f04abc2ad25e52f30b5e2bffa286b019
diff --git a/tests/crashes/133639.rs b/tests/crashes/133639.rs
deleted file mode 100644
index d522b0730cf..00000000000
--- a/tests/crashes/133639.rs
+++ /dev/null
@@ -1,33 +0,0 @@
-//@ known-bug: #133639
-
-#![feature(with_negative_coherence)]
-#![feature(min_specialization)]
-#![feature(generic_const_exprs)]
-
-#![crate_type = "lib"]
-use std::str::FromStr;
-
-struct a<const b: bool>;
-
-trait c {}
-
-impl<const d: u32> FromStr for e<d>
-where
-    a<{ d <= 2 }>: c,
-{
-    type Err = ();
-    fn from_str(f: &str) -> Result<Self, Self::Err> {
-        unimplemented!()
-    }
-}
-struct e<const d: u32>;
-
-impl<const d: u32> FromStr for e<d>
-where
-    a<{ d <= 2 }>: c,
-{
-    type Err = ();
-    fn from_str(f: &str) -> Result<Self, Self::Err> {
-        unimplemented!()
-    }
-}
diff --git a/tests/rustdoc-ui/lints/feature-gate-rustdoc_missing_doc_code_examples.stderr b/tests/rustdoc-ui/lints/feature-gate-rustdoc_missing_doc_code_examples.stderr
index 67540949f4d..e017b1f34a1 100644
--- a/tests/rustdoc-ui/lints/feature-gate-rustdoc_missing_doc_code_examples.stderr
+++ b/tests/rustdoc-ui/lints/feature-gate-rustdoc_missing_doc_code_examples.stderr
@@ -1,8 +1,8 @@
 error: unknown lint: `rustdoc::missing_doc_code_examples`
-  --> $DIR/feature-gate-rustdoc_missing_doc_code_examples.rs:4:1
+  --> $DIR/feature-gate-rustdoc_missing_doc_code_examples.rs:4:10
    |
 LL | #![allow(rustdoc::missing_doc_code_examples)]
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: the `rustdoc::missing_doc_code_examples` lint is unstable
    = note: see issue #101730 <https://github.com/rust-lang/rust/issues/101730> for more information
diff --git a/tests/ui/attr-bad-crate-attr.rs b/tests/ui/attr-bad-crate-attr.rs
deleted file mode 100644
index b9100ecfb67..00000000000
--- a/tests/ui/attr-bad-crate-attr.rs
+++ /dev/null
@@ -1,4 +0,0 @@
-//@ error-pattern: expected item
-
-#![attr = "val"]
-#[attr = "val"] // Unterminated
diff --git a/tests/ui/attr-shebang.rs b/tests/ui/attr-shebang.rs
deleted file mode 100644
index 67c371aeaac..00000000000
--- a/tests/ui/attr-shebang.rs
+++ /dev/null
@@ -1,5 +0,0 @@
-//@ run-pass
-
-#![allow(stable_features)]
-#![feature(rust1)]
-pub fn main() { }
diff --git a/tests/ui/attributes/attr-bad-crate-attr.rs b/tests/ui/attributes/attr-bad-crate-attr.rs
new file mode 100644
index 00000000000..9de0abca9a7
--- /dev/null
+++ b/tests/ui/attributes/attr-bad-crate-attr.rs
@@ -0,0 +1,9 @@
+//! Check that we permit a crate-level inner attribute but reject a dangling outer attribute which
+//! does not have a following thing that it can target.
+//!
+//! See <https://doc.rust-lang.org/reference/attributes.html>.
+
+//@ error-pattern: expected item
+
+#![attr = "val"]
+#[attr = "val"] // Unterminated
diff --git a/tests/ui/attr-bad-crate-attr.stderr b/tests/ui/attributes/attr-bad-crate-attr.stderr
index 9df991f71b3..69eabd32230 100644
--- a/tests/ui/attr-bad-crate-attr.stderr
+++ b/tests/ui/attributes/attr-bad-crate-attr.stderr
@@ -1,5 +1,5 @@
 error: expected item after attributes
-  --> $DIR/attr-bad-crate-attr.rs:4:1
+  --> $DIR/attr-bad-crate-attr.rs:9:1
    |
 LL | #[attr = "val"] // Unterminated
    | ^^^^^^^^^^^^^^^
diff --git a/tests/ui/attributes/attr-shebang.rs b/tests/ui/attributes/attr-shebang.rs
new file mode 100644
index 00000000000..af446dc56e3
--- /dev/null
+++ b/tests/ui/attributes/attr-shebang.rs
@@ -0,0 +1,7 @@
+//! Check that we accept crate-level inner attributes with the `#![..]` shebang syntax.
+
+//@ check-pass
+
+#![allow(stable_features)]
+#![feature(rust1)]
+pub fn main() { }
diff --git a/tests/ui/attr-usage-inline.rs b/tests/ui/attributes/inline/attr-usage-inline.rs
index 674c12454cd..d8ca0fce163 100644
--- a/tests/ui/attr-usage-inline.rs
+++ b/tests/ui/attributes/inline/attr-usage-inline.rs
@@ -1,4 +1,5 @@
-#![allow(dead_code)]
+//! Check that `#[inline]` attribute can only be applied to fn-like targets (e.g. function or
+//! closure), and when misapplied to other targets an error is emitted.
 
 #[inline]
 fn f() {}
diff --git a/tests/ui/attr-usage-inline.stderr b/tests/ui/attributes/inline/attr-usage-inline.stderr
index 22a0bf47e20..2123438032c 100644
--- a/tests/ui/attr-usage-inline.stderr
+++ b/tests/ui/attributes/inline/attr-usage-inline.stderr
@@ -1,5 +1,5 @@
 error[E0518]: attribute should be applied to function or closure
-  --> $DIR/attr-usage-inline.rs:6:1
+  --> $DIR/attr-usage-inline.rs:7:1
    |
 LL | #[inline]
    | ^^^^^^^^^
@@ -7,7 +7,7 @@ LL | struct S;
    | --------- not a function or closure
 
 error[E0518]: attribute should be applied to function or closure
-  --> $DIR/attr-usage-inline.rs:20:1
+  --> $DIR/attr-usage-inline.rs:21:1
    |
 LL | #[inline]
    | ^^^^^^^^^ not a function or closure
diff --git a/tests/ui/const-generics/generic_const_exprs/specialization-fuzzing-ice-133639.rs b/tests/ui/const-generics/generic_const_exprs/specialization-fuzzing-ice-133639.rs
new file mode 100644
index 00000000000..d3ae863bee9
--- /dev/null
+++ b/tests/ui/const-generics/generic_const_exprs/specialization-fuzzing-ice-133639.rs
@@ -0,0 +1,19 @@
+//@ check-pass
+
+// Regression test for #133639.
+
+#![feature(with_negative_coherence)]
+#![feature(min_specialization)]
+#![feature(generic_const_exprs)]
+//~^ WARNING the feature `generic_const_exprs` is incomplete
+
+#![crate_type = "lib"]
+trait Trait {}
+struct A<const B: bool>;
+
+trait C {}
+
+impl<const D: u32> Trait for E<D> where A<{ D <= 2 }>: C {}
+struct E<const D: u32>;
+
+impl<const D: u32> Trait for E<D> where A<{ D <= 2 }>: C {}
diff --git a/tests/ui/const-generics/generic_const_exprs/specialization-fuzzing-ice-133639.stderr b/tests/ui/const-generics/generic_const_exprs/specialization-fuzzing-ice-133639.stderr
new file mode 100644
index 00000000000..f17b248d856
--- /dev/null
+++ b/tests/ui/const-generics/generic_const_exprs/specialization-fuzzing-ice-133639.stderr
@@ -0,0 +1,11 @@
+warning: the feature `generic_const_exprs` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/specialization-fuzzing-ice-133639.rs:7:12
+   |
+LL | #![feature(generic_const_exprs)]
+   |            ^^^^^^^^^^^^^^^^^^^
+   |
+   = note: see issue #76560 <https://github.com/rust-lang/rust/issues/76560> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
+warning: 1 warning emitted
+
diff --git a/tests/ui/const-generics/min_const_generics/param-env-eager-norm-dedup.rs b/tests/ui/const-generics/min_const_generics/param-env-eager-norm-dedup.rs
index 9600b3875ba..2e97e3fe004 100644
--- a/tests/ui/const-generics/min_const_generics/param-env-eager-norm-dedup.rs
+++ b/tests/ui/const-generics/min_const_generics/param-env-eager-norm-dedup.rs
@@ -1,3 +1,6 @@
+//@ revisions: current next
+//@ ignore-compare-mode-next-solver (explicit revisions)
+//@[next] compile-flags: -Znext-solver
 //@ check-pass
 
 // This caused a regression in a crater run in #132325.
diff --git a/tests/ui/diagnostic_namespace/do_not_recommend/as_expression.current.stderr b/tests/ui/diagnostic_namespace/do_not_recommend/as_expression.current.stderr
index 5d0c1826411..28e7975c7a2 100644
--- a/tests/ui/diagnostic_namespace/do_not_recommend/as_expression.current.stderr
+++ b/tests/ui/diagnostic_namespace/do_not_recommend/as_expression.current.stderr
@@ -1,5 +1,5 @@
 error[E0277]: the trait bound `&str: AsExpression<Integer>` is not satisfied
-  --> $DIR/as_expression.rs:57:15
+  --> $DIR/as_expression.rs:55:15
    |
 LL |     SelectInt.check("bar");
    |               ^^^^^ the trait `AsExpression<Integer>` is not implemented for `&str`
diff --git a/tests/ui/diagnostic_namespace/do_not_recommend/as_expression.next.stderr b/tests/ui/diagnostic_namespace/do_not_recommend/as_expression.next.stderr
index 1e1eae852f9..1b76669ccb0 100644
--- a/tests/ui/diagnostic_namespace/do_not_recommend/as_expression.next.stderr
+++ b/tests/ui/diagnostic_namespace/do_not_recommend/as_expression.next.stderr
@@ -1,5 +1,5 @@
 error[E0277]: the trait bound `&str: AsExpression<<SelectInt as Expression>::SqlType>` is not satisfied
-  --> $DIR/as_expression.rs:57:21
+  --> $DIR/as_expression.rs:55:21
    |
 LL |     SelectInt.check("bar");
    |               ----- ^^^^^ the trait `AsExpression<<SelectInt as Expression>::SqlType>` is not implemented for `&str`
@@ -8,7 +8,7 @@ LL |     SelectInt.check("bar");
    |
    = help: the trait `AsExpression<Text>` is implemented for `&str`
 note: required by a bound in `Foo::check`
-  --> $DIR/as_expression.rs:48:12
+  --> $DIR/as_expression.rs:46:12
    |
 LL |     fn check<T>(&self, _: T) -> <T as AsExpression<<Self as Expression>::SqlType>>::Expression
    |        ----- required by a bound in this associated function
@@ -17,7 +17,7 @@ LL |         T: AsExpression<Self::SqlType>,
    |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `Foo::check`
 
 error[E0277]: the trait bound `&str: AsExpression<Integer>` is not satisfied
-  --> $DIR/as_expression.rs:57:15
+  --> $DIR/as_expression.rs:55:15
    |
 LL |     SelectInt.check("bar");
    |               ^^^^^ the trait `AsExpression<Integer>` is not implemented for `&str`
@@ -27,7 +27,7 @@ LL |     SelectInt.check("bar");
    = help: for that trait implementation, expected `Text`, found `Integer`
 
 error[E0271]: type mismatch resolving `<SelectInt as Expression>::SqlType == Text`
-  --> $DIR/as_expression.rs:57:5
+  --> $DIR/as_expression.rs:55:5
    |
 LL |     SelectInt.check("bar");
    |     ^^^^^^^^^^^^^^^^^^^^^^ expected `Text`, found `Integer`
diff --git a/tests/ui/diagnostic_namespace/do_not_recommend/as_expression.rs b/tests/ui/diagnostic_namespace/do_not_recommend/as_expression.rs
index 37b4429f694..583b3c4675a 100644
--- a/tests/ui/diagnostic_namespace/do_not_recommend/as_expression.rs
+++ b/tests/ui/diagnostic_namespace/do_not_recommend/as_expression.rs
@@ -2,8 +2,6 @@
 //@ ignore-compare-mode-next-solver (explicit revisions)
 //@[next] compile-flags: -Znext-solver
 
-#![feature(do_not_recommend)]
-
 pub trait Expression {
     type SqlType;
 }
diff --git a/tests/ui/diagnostic_namespace/do_not_recommend/do_not_apply_attribute_without_feature_flag.rs b/tests/ui/diagnostic_namespace/do_not_recommend/do_not_apply_attribute_without_feature_flag.rs
deleted file mode 100644
index 5548fa2f52e..00000000000
--- a/tests/ui/diagnostic_namespace/do_not_recommend/do_not_apply_attribute_without_feature_flag.rs
+++ /dev/null
@@ -1,21 +0,0 @@
-#![allow(unknown_or_malformed_diagnostic_attributes)]
-
-trait Foo {}
-
-#[diagnostic::do_not_recommend]
-impl<A> Foo for (A,) {}
-
-#[diagnostic::do_not_recommend]
-impl<A, B> Foo for (A, B) {}
-
-#[diagnostic::do_not_recommend]
-impl<A, B, C> Foo for (A, B, C) {}
-
-impl Foo for i32 {}
-
-fn check(a: impl Foo) {}
-
-fn main() {
-    check(());
-    //~^ ERROR the trait bound `(): Foo` is not satisfied
-}
diff --git a/tests/ui/diagnostic_namespace/do_not_recommend/do_not_apply_attribute_without_feature_flag.stderr b/tests/ui/diagnostic_namespace/do_not_recommend/do_not_apply_attribute_without_feature_flag.stderr
deleted file mode 100644
index be17476524a..00000000000
--- a/tests/ui/diagnostic_namespace/do_not_recommend/do_not_apply_attribute_without_feature_flag.stderr
+++ /dev/null
@@ -1,25 +0,0 @@
-error[E0277]: the trait bound `(): Foo` is not satisfied
-  --> $DIR/do_not_apply_attribute_without_feature_flag.rs:19:11
-   |
-LL |     check(());
-   |     ----- ^^ the trait `Foo` is not implemented for `()`
-   |     |
-   |     required by a bound introduced by this call
-   |
-   = help: the following other types implement trait `Foo`:
-             (A, B)
-             (A, B, C)
-             (A,)
-note: required by a bound in `check`
-  --> $DIR/do_not_apply_attribute_without_feature_flag.rs:16:18
-   |
-LL | fn check(a: impl Foo) {}
-   |                  ^^^ required by this bound in `check`
-help: use a unary tuple instead
-   |
-LL |     check(((),));
-   |           +  ++
-
-error: aborting due to 1 previous error
-
-For more information about this error, try `rustc --explain E0277`.
diff --git a/tests/ui/diagnostic_namespace/do_not_recommend/does_not_acccept_args.current.stderr b/tests/ui/diagnostic_namespace/do_not_recommend/does_not_acccept_args.current.stderr
new file mode 100644
index 00000000000..47597a5d405
--- /dev/null
+++ b/tests/ui/diagnostic_namespace/do_not_recommend/does_not_acccept_args.current.stderr
@@ -0,0 +1,22 @@
+warning: `#[diagnostic::do_not_recommend]` does not expect any arguments
+  --> $DIR/does_not_acccept_args.rs:10:1
+   |
+LL | #[diagnostic::do_not_recommend(not_accepted)]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: `#[warn(unknown_or_malformed_diagnostic_attributes)]` on by default
+
+warning: `#[diagnostic::do_not_recommend]` does not expect any arguments
+  --> $DIR/does_not_acccept_args.rs:14:1
+   |
+LL | #[diagnostic::do_not_recommend(not_accepted = "foo")]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+warning: `#[diagnostic::do_not_recommend]` does not expect any arguments
+  --> $DIR/does_not_acccept_args.rs:18:1
+   |
+LL | #[diagnostic::do_not_recommend(not_accepted(42))]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+warning: 3 warnings emitted
+
diff --git a/tests/ui/diagnostic_namespace/do_not_recommend/does_not_acccept_args.next.stderr b/tests/ui/diagnostic_namespace/do_not_recommend/does_not_acccept_args.next.stderr
new file mode 100644
index 00000000000..47597a5d405
--- /dev/null
+++ b/tests/ui/diagnostic_namespace/do_not_recommend/does_not_acccept_args.next.stderr
@@ -0,0 +1,22 @@
+warning: `#[diagnostic::do_not_recommend]` does not expect any arguments
+  --> $DIR/does_not_acccept_args.rs:10:1
+   |
+LL | #[diagnostic::do_not_recommend(not_accepted)]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: `#[warn(unknown_or_malformed_diagnostic_attributes)]` on by default
+
+warning: `#[diagnostic::do_not_recommend]` does not expect any arguments
+  --> $DIR/does_not_acccept_args.rs:14:1
+   |
+LL | #[diagnostic::do_not_recommend(not_accepted = "foo")]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+warning: `#[diagnostic::do_not_recommend]` does not expect any arguments
+  --> $DIR/does_not_acccept_args.rs:18:1
+   |
+LL | #[diagnostic::do_not_recommend(not_accepted(42))]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+warning: 3 warnings emitted
+
diff --git a/tests/ui/diagnostic_namespace/do_not_recommend/does_not_acccept_args.rs b/tests/ui/diagnostic_namespace/do_not_recommend/does_not_acccept_args.rs
new file mode 100644
index 00000000000..eeff5e2e6e8
--- /dev/null
+++ b/tests/ui/diagnostic_namespace/do_not_recommend/does_not_acccept_args.rs
@@ -0,0 +1,22 @@
+//@ check-pass
+//@ revisions: current next
+//@ ignore-compare-mode-next-solver (explicit revisions)
+//@[next] compile-flags: -Znext-solver
+
+trait Foo {}
+trait Bar {}
+trait Baz {}
+
+#[diagnostic::do_not_recommend(not_accepted)]
+//~^ WARNING `#[diagnostic::do_not_recommend]` does not expect any arguments
+impl<T> Foo for T where T: Send {}
+
+#[diagnostic::do_not_recommend(not_accepted = "foo")]
+//~^ WARNING `#[diagnostic::do_not_recommend]` does not expect any arguments
+impl<T> Bar for T where T: Send {}
+
+#[diagnostic::do_not_recommend(not_accepted(42))]
+//~^ WARNING `#[diagnostic::do_not_recommend]` does not expect any arguments
+impl<T> Baz for T where T: Send {}
+
+fn main() {}
diff --git a/tests/ui/diagnostic_namespace/do_not_recommend/feature-gate-do_not_recommend.rs b/tests/ui/diagnostic_namespace/do_not_recommend/feature-gate-do_not_recommend.rs
deleted file mode 100644
index 5a26d28188c..00000000000
--- a/tests/ui/diagnostic_namespace/do_not_recommend/feature-gate-do_not_recommend.rs
+++ /dev/null
@@ -1,17 +0,0 @@
-#![feature(do_not_recommend)]
-
-pub trait Foo {}
-
-impl Foo for i32 {}
-
-pub trait Bar {}
-
-#[diagnostic::do_not_recommend]
-impl<T: Foo> Bar for T {}
-
-fn stuff<T: Bar>(_: T) {}
-
-fn main() {
-    stuff(1u8);
-    //~^ the trait bound `u8: Bar` is not satisfied
-}
diff --git a/tests/ui/diagnostic_namespace/do_not_recommend/feature-gate-do_not_recommend.stderr b/tests/ui/diagnostic_namespace/do_not_recommend/feature-gate-do_not_recommend.stderr
deleted file mode 100644
index 3951231fa2e..00000000000
--- a/tests/ui/diagnostic_namespace/do_not_recommend/feature-gate-do_not_recommend.stderr
+++ /dev/null
@@ -1,15 +0,0 @@
-error[E0277]: the trait bound `u8: Bar` is not satisfied
-  --> $DIR/feature-gate-do_not_recommend.rs:15:11
-   |
-LL |     stuff(1u8);
-   |           ^^^ the trait `Bar` is not implemented for `u8`
-   |
-note: required by a bound in `stuff`
-  --> $DIR/feature-gate-do_not_recommend.rs:12:13
-   |
-LL | fn stuff<T: Bar>(_: T) {}
-   |             ^^^ required by this bound in `stuff`
-
-error: aborting due to 1 previous error
-
-For more information about this error, try `rustc --explain E0277`.
diff --git a/tests/ui/diagnostic_namespace/do_not_recommend/incorrect-locations.stderr b/tests/ui/diagnostic_namespace/do_not_recommend/incorrect-locations.current.stderr
index c83fd46db58..ee6ebabadd9 100644
--- a/tests/ui/diagnostic_namespace/do_not_recommend/incorrect-locations.stderr
+++ b/tests/ui/diagnostic_namespace/do_not_recommend/incorrect-locations.current.stderr
@@ -1,5 +1,5 @@
 warning: `#[diagnostic::do_not_recommend]` can only be placed on trait implementations
-  --> $DIR/incorrect-locations.rs:4:1
+  --> $DIR/incorrect-locations.rs:6:1
    |
 LL | #[diagnostic::do_not_recommend]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -7,46 +7,52 @@ LL | #[diagnostic::do_not_recommend]
    = note: `#[warn(unknown_or_malformed_diagnostic_attributes)]` on by default
 
 warning: `#[diagnostic::do_not_recommend]` can only be placed on trait implementations
-  --> $DIR/incorrect-locations.rs:8:1
+  --> $DIR/incorrect-locations.rs:10:1
    |
 LL | #[diagnostic::do_not_recommend]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: `#[diagnostic::do_not_recommend]` can only be placed on trait implementations
-  --> $DIR/incorrect-locations.rs:12:1
+  --> $DIR/incorrect-locations.rs:14:1
    |
 LL | #[diagnostic::do_not_recommend]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: `#[diagnostic::do_not_recommend]` can only be placed on trait implementations
-  --> $DIR/incorrect-locations.rs:16:1
+  --> $DIR/incorrect-locations.rs:18:1
    |
 LL | #[diagnostic::do_not_recommend]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: `#[diagnostic::do_not_recommend]` can only be placed on trait implementations
-  --> $DIR/incorrect-locations.rs:20:1
+  --> $DIR/incorrect-locations.rs:22:1
    |
 LL | #[diagnostic::do_not_recommend]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: `#[diagnostic::do_not_recommend]` can only be placed on trait implementations
-  --> $DIR/incorrect-locations.rs:24:1
+  --> $DIR/incorrect-locations.rs:26:1
    |
 LL | #[diagnostic::do_not_recommend]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: `#[diagnostic::do_not_recommend]` can only be placed on trait implementations
-  --> $DIR/incorrect-locations.rs:28:1
+  --> $DIR/incorrect-locations.rs:30:1
    |
 LL | #[diagnostic::do_not_recommend]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: `#[diagnostic::do_not_recommend]` can only be placed on trait implementations
-  --> $DIR/incorrect-locations.rs:32:1
+  --> $DIR/incorrect-locations.rs:34:1
    |
 LL | #[diagnostic::do_not_recommend]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-warning: 8 warnings emitted
+warning: `#[diagnostic::do_not_recommend]` can only be placed on trait implementations
+  --> $DIR/incorrect-locations.rs:38:1
+   |
+LL | #[diagnostic::do_not_recommend]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+warning: 9 warnings emitted
 
diff --git a/tests/ui/diagnostic_namespace/do_not_recommend/incorrect-locations.next.stderr b/tests/ui/diagnostic_namespace/do_not_recommend/incorrect-locations.next.stderr
new file mode 100644
index 00000000000..ee6ebabadd9
--- /dev/null
+++ b/tests/ui/diagnostic_namespace/do_not_recommend/incorrect-locations.next.stderr
@@ -0,0 +1,58 @@
+warning: `#[diagnostic::do_not_recommend]` can only be placed on trait implementations
+  --> $DIR/incorrect-locations.rs:6:1
+   |
+LL | #[diagnostic::do_not_recommend]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: `#[warn(unknown_or_malformed_diagnostic_attributes)]` on by default
+
+warning: `#[diagnostic::do_not_recommend]` can only be placed on trait implementations
+  --> $DIR/incorrect-locations.rs:10:1
+   |
+LL | #[diagnostic::do_not_recommend]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+warning: `#[diagnostic::do_not_recommend]` can only be placed on trait implementations
+  --> $DIR/incorrect-locations.rs:14:1
+   |
+LL | #[diagnostic::do_not_recommend]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+warning: `#[diagnostic::do_not_recommend]` can only be placed on trait implementations
+  --> $DIR/incorrect-locations.rs:18:1
+   |
+LL | #[diagnostic::do_not_recommend]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+warning: `#[diagnostic::do_not_recommend]` can only be placed on trait implementations
+  --> $DIR/incorrect-locations.rs:22:1
+   |
+LL | #[diagnostic::do_not_recommend]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+warning: `#[diagnostic::do_not_recommend]` can only be placed on trait implementations
+  --> $DIR/incorrect-locations.rs:26:1
+   |
+LL | #[diagnostic::do_not_recommend]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+warning: `#[diagnostic::do_not_recommend]` can only be placed on trait implementations
+  --> $DIR/incorrect-locations.rs:30:1
+   |
+LL | #[diagnostic::do_not_recommend]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+warning: `#[diagnostic::do_not_recommend]` can only be placed on trait implementations
+  --> $DIR/incorrect-locations.rs:34:1
+   |
+LL | #[diagnostic::do_not_recommend]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+warning: `#[diagnostic::do_not_recommend]` can only be placed on trait implementations
+  --> $DIR/incorrect-locations.rs:38:1
+   |
+LL | #[diagnostic::do_not_recommend]
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+warning: 9 warnings emitted
+
diff --git a/tests/ui/diagnostic_namespace/do_not_recommend/incorrect-locations.rs b/tests/ui/diagnostic_namespace/do_not_recommend/incorrect-locations.rs
index 400ef83873e..1cf436aa2af 100644
--- a/tests/ui/diagnostic_namespace/do_not_recommend/incorrect-locations.rs
+++ b/tests/ui/diagnostic_namespace/do_not_recommend/incorrect-locations.rs
@@ -1,5 +1,7 @@
 //@ check-pass
-#![feature(do_not_recommend)]
+//@ revisions: current next
+//@ ignore-compare-mode-next-solver (explicit revisions)
+//@[next] compile-flags: -Znext-solver
 
 #[diagnostic::do_not_recommend]
 //~^WARN `#[diagnostic::do_not_recommend]` can only be placed
@@ -19,6 +21,10 @@ enum Enum {}
 
 #[diagnostic::do_not_recommend]
 //~^WARN `#[diagnostic::do_not_recommend]` can only be placed
+impl Enum {}
+
+#[diagnostic::do_not_recommend]
+//~^WARN `#[diagnostic::do_not_recommend]` can only be placed
 extern "C" {}
 
 #[diagnostic::do_not_recommend]
diff --git a/tests/ui/diagnostic_namespace/do_not_recommend/nested.current.stderr b/tests/ui/diagnostic_namespace/do_not_recommend/nested.current.stderr
new file mode 100644
index 00000000000..b14c68d6897
--- /dev/null
+++ b/tests/ui/diagnostic_namespace/do_not_recommend/nested.current.stderr
@@ -0,0 +1,15 @@
+error[E0277]: the trait bound `(): Root` is not satisfied
+  --> $DIR/nested.rs:21:18
+   |
+LL |     needs_root::<()>();
+   |                  ^^ the trait `Root` is not implemented for `()`
+   |
+note: required by a bound in `needs_root`
+  --> $DIR/nested.rs:18:18
+   |
+LL | fn needs_root<T: Root>() {}
+   |                  ^^^^ required by this bound in `needs_root`
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0277`.
diff --git a/tests/ui/diagnostic_namespace/do_not_recommend/nested.next.stderr b/tests/ui/diagnostic_namespace/do_not_recommend/nested.next.stderr
new file mode 100644
index 00000000000..b14c68d6897
--- /dev/null
+++ b/tests/ui/diagnostic_namespace/do_not_recommend/nested.next.stderr
@@ -0,0 +1,15 @@
+error[E0277]: the trait bound `(): Root` is not satisfied
+  --> $DIR/nested.rs:21:18
+   |
+LL |     needs_root::<()>();
+   |                  ^^ the trait `Root` is not implemented for `()`
+   |
+note: required by a bound in `needs_root`
+  --> $DIR/nested.rs:18:18
+   |
+LL | fn needs_root<T: Root>() {}
+   |                  ^^^^ required by this bound in `needs_root`
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0277`.
diff --git a/tests/ui/diagnostic_namespace/do_not_recommend/nested.rs b/tests/ui/diagnostic_namespace/do_not_recommend/nested.rs
new file mode 100644
index 00000000000..6534157d1fb
--- /dev/null
+++ b/tests/ui/diagnostic_namespace/do_not_recommend/nested.rs
@@ -0,0 +1,23 @@
+//@ revisions: current next
+//@ ignore-compare-mode-next-solver (explicit revisions)
+//@[next] compile-flags: -Znext-solver
+
+trait Root {}
+trait DontRecommend {}
+trait Other {}
+trait Child {}
+
+#[diagnostic::do_not_recommend]
+impl<T> Root for T where T: DontRecommend {}
+
+impl<T> DontRecommend for T where T: Other {}
+
+#[diagnostic::do_not_recommend]
+impl<T> Other for T where T: Child {}
+
+fn needs_root<T: Root>() {}
+
+fn main() {
+    needs_root::<()>();
+    //~^ ERROR the trait bound `(): Root` is not satisfied
+}
diff --git a/tests/ui/diagnostic_namespace/do_not_recommend/simple.current.stderr b/tests/ui/diagnostic_namespace/do_not_recommend/simple.current.stderr
index 729cb5694e2..884b13c17b8 100644
--- a/tests/ui/diagnostic_namespace/do_not_recommend/simple.current.stderr
+++ b/tests/ui/diagnostic_namespace/do_not_recommend/simple.current.stderr
@@ -1,11 +1,11 @@
 error[E0277]: the trait bound `*mut (): Foo` is not satisfied
-  --> $DIR/simple.rs:17:17
+  --> $DIR/simple.rs:15:17
    |
 LL |     needs_foo::<*mut ()>();
    |                 ^^^^^^^ the trait `Foo` is not implemented for `*mut ()`
    |
 note: required by a bound in `needs_foo`
-  --> $DIR/simple.rs:12:17
+  --> $DIR/simple.rs:10:17
    |
 LL | fn needs_foo<T: Foo>() {}
    |                 ^^^ required by this bound in `needs_foo`
diff --git a/tests/ui/diagnostic_namespace/do_not_recommend/simple.next.stderr b/tests/ui/diagnostic_namespace/do_not_recommend/simple.next.stderr
index 729cb5694e2..884b13c17b8 100644
--- a/tests/ui/diagnostic_namespace/do_not_recommend/simple.next.stderr
+++ b/tests/ui/diagnostic_namespace/do_not_recommend/simple.next.stderr
@@ -1,11 +1,11 @@
 error[E0277]: the trait bound `*mut (): Foo` is not satisfied
-  --> $DIR/simple.rs:17:17
+  --> $DIR/simple.rs:15:17
    |
 LL |     needs_foo::<*mut ()>();
    |                 ^^^^^^^ the trait `Foo` is not implemented for `*mut ()`
    |
 note: required by a bound in `needs_foo`
-  --> $DIR/simple.rs:12:17
+  --> $DIR/simple.rs:10:17
    |
 LL | fn needs_foo<T: Foo>() {}
    |                 ^^^ required by this bound in `needs_foo`
diff --git a/tests/ui/diagnostic_namespace/do_not_recommend/simple.rs b/tests/ui/diagnostic_namespace/do_not_recommend/simple.rs
index 780649b009c..6bca2b724d2 100644
--- a/tests/ui/diagnostic_namespace/do_not_recommend/simple.rs
+++ b/tests/ui/diagnostic_namespace/do_not_recommend/simple.rs
@@ -2,8 +2,6 @@
 //@ ignore-compare-mode-next-solver (explicit revisions)
 //@[next] compile-flags: -Znext-solver
 
-#![feature(do_not_recommend)]
-
 trait Foo {}
 
 #[diagnostic::do_not_recommend]
diff --git a/tests/ui/diagnostic_namespace/do_not_recommend/stacked.current.stderr b/tests/ui/diagnostic_namespace/do_not_recommend/stacked.current.stderr
index 41a10a61e1d..d8605806395 100644
--- a/tests/ui/diagnostic_namespace/do_not_recommend/stacked.current.stderr
+++ b/tests/ui/diagnostic_namespace/do_not_recommend/stacked.current.stderr
@@ -1,11 +1,11 @@
 error[E0277]: the trait bound `(): Root` is not satisfied
-  --> $DIR/stacked.rs:19:18
+  --> $DIR/stacked.rs:17:18
    |
 LL |     needs_root::<()>();
    |                  ^^ the trait `Root` is not implemented for `()`
    |
 note: required by a bound in `needs_root`
-  --> $DIR/stacked.rs:16:18
+  --> $DIR/stacked.rs:14:18
    |
 LL | fn needs_root<T: Root>() {}
    |                  ^^^^ required by this bound in `needs_root`
diff --git a/tests/ui/diagnostic_namespace/do_not_recommend/stacked.next.stderr b/tests/ui/diagnostic_namespace/do_not_recommend/stacked.next.stderr
index 41a10a61e1d..d8605806395 100644
--- a/tests/ui/diagnostic_namespace/do_not_recommend/stacked.next.stderr
+++ b/tests/ui/diagnostic_namespace/do_not_recommend/stacked.next.stderr
@@ -1,11 +1,11 @@
 error[E0277]: the trait bound `(): Root` is not satisfied
-  --> $DIR/stacked.rs:19:18
+  --> $DIR/stacked.rs:17:18
    |
 LL |     needs_root::<()>();
    |                  ^^ the trait `Root` is not implemented for `()`
    |
 note: required by a bound in `needs_root`
-  --> $DIR/stacked.rs:16:18
+  --> $DIR/stacked.rs:14:18
    |
 LL | fn needs_root<T: Root>() {}
    |                  ^^^^ required by this bound in `needs_root`
diff --git a/tests/ui/diagnostic_namespace/do_not_recommend/stacked.rs b/tests/ui/diagnostic_namespace/do_not_recommend/stacked.rs
index fc355bdc4e2..842e04b9d90 100644
--- a/tests/ui/diagnostic_namespace/do_not_recommend/stacked.rs
+++ b/tests/ui/diagnostic_namespace/do_not_recommend/stacked.rs
@@ -2,8 +2,6 @@
 //@ ignore-compare-mode-next-solver (explicit revisions)
 //@[next] compile-flags: -Znext-solver
 
-#![feature(do_not_recommend)]
-
 trait Root {}
 trait DontRecommend {}
 trait Other {}
diff --git a/tests/ui/diagnostic_namespace/do_not_recommend/supress_suggestions_in_help.current.stderr b/tests/ui/diagnostic_namespace/do_not_recommend/supress_suggestions_in_help.current.stderr
index ca9a6ebc1c4..95ccbb92a89 100644
--- a/tests/ui/diagnostic_namespace/do_not_recommend/supress_suggestions_in_help.current.stderr
+++ b/tests/ui/diagnostic_namespace/do_not_recommend/supress_suggestions_in_help.current.stderr
@@ -1,5 +1,5 @@
 error[E0277]: the trait bound `(): Foo` is not satisfied
-  --> $DIR/supress_suggestions_in_help.rs:23:11
+  --> $DIR/supress_suggestions_in_help.rs:21:11
    |
 LL |     check(());
    |     ----- ^^ the trait `Foo` is not implemented for `()`
@@ -8,7 +8,7 @@ LL |     check(());
    |
    = help: the trait `Foo` is implemented for `i32`
 note: required by a bound in `check`
-  --> $DIR/supress_suggestions_in_help.rs:20:18
+  --> $DIR/supress_suggestions_in_help.rs:18:18
    |
 LL | fn check(a: impl Foo) {}
    |                  ^^^ required by this bound in `check`
diff --git a/tests/ui/diagnostic_namespace/do_not_recommend/supress_suggestions_in_help.next.stderr b/tests/ui/diagnostic_namespace/do_not_recommend/supress_suggestions_in_help.next.stderr
index ca9a6ebc1c4..95ccbb92a89 100644
--- a/tests/ui/diagnostic_namespace/do_not_recommend/supress_suggestions_in_help.next.stderr
+++ b/tests/ui/diagnostic_namespace/do_not_recommend/supress_suggestions_in_help.next.stderr
@@ -1,5 +1,5 @@
 error[E0277]: the trait bound `(): Foo` is not satisfied
-  --> $DIR/supress_suggestions_in_help.rs:23:11
+  --> $DIR/supress_suggestions_in_help.rs:21:11
    |
 LL |     check(());
    |     ----- ^^ the trait `Foo` is not implemented for `()`
@@ -8,7 +8,7 @@ LL |     check(());
    |
    = help: the trait `Foo` is implemented for `i32`
 note: required by a bound in `check`
-  --> $DIR/supress_suggestions_in_help.rs:20:18
+  --> $DIR/supress_suggestions_in_help.rs:18:18
    |
 LL | fn check(a: impl Foo) {}
    |                  ^^^ required by this bound in `check`
diff --git a/tests/ui/diagnostic_namespace/do_not_recommend/supress_suggestions_in_help.rs b/tests/ui/diagnostic_namespace/do_not_recommend/supress_suggestions_in_help.rs
index ef6f255c351..2c7c1516123 100644
--- a/tests/ui/diagnostic_namespace/do_not_recommend/supress_suggestions_in_help.rs
+++ b/tests/ui/diagnostic_namespace/do_not_recommend/supress_suggestions_in_help.rs
@@ -2,8 +2,6 @@
 //@ ignore-compare-mode-next-solver (explicit revisions)
 //@[next] compile-flags: -Znext-solver
 
-#![feature(do_not_recommend)]
-
 trait Foo {}
 
 #[diagnostic::do_not_recommend]
diff --git a/tests/ui/diagnostic_namespace/do_not_recommend/type_mismatch.current.stderr b/tests/ui/diagnostic_namespace/do_not_recommend/type_mismatch.current.stderr
index bcede8a255f..b53febbb71a 100644
--- a/tests/ui/diagnostic_namespace/do_not_recommend/type_mismatch.current.stderr
+++ b/tests/ui/diagnostic_namespace/do_not_recommend/type_mismatch.current.stderr
@@ -1,11 +1,11 @@
 error[E0277]: Very important message!
-  --> $DIR/type_mismatch.rs:25:14
+  --> $DIR/type_mismatch.rs:23:14
    |
 LL |     verify::<u8>();
    |              ^^ the trait `TheImportantOne` is not implemented for `u8`
    |
 note: required by a bound in `verify`
-  --> $DIR/type_mismatch.rs:22:14
+  --> $DIR/type_mismatch.rs:20:14
    |
 LL | fn verify<T: TheImportantOne>() {}
    |              ^^^^^^^^^^^^^^^ required by this bound in `verify`
diff --git a/tests/ui/diagnostic_namespace/do_not_recommend/type_mismatch.next.stderr b/tests/ui/diagnostic_namespace/do_not_recommend/type_mismatch.next.stderr
index bcede8a255f..b53febbb71a 100644
--- a/tests/ui/diagnostic_namespace/do_not_recommend/type_mismatch.next.stderr
+++ b/tests/ui/diagnostic_namespace/do_not_recommend/type_mismatch.next.stderr
@@ -1,11 +1,11 @@
 error[E0277]: Very important message!
-  --> $DIR/type_mismatch.rs:25:14
+  --> $DIR/type_mismatch.rs:23:14
    |
 LL |     verify::<u8>();
    |              ^^ the trait `TheImportantOne` is not implemented for `u8`
    |
 note: required by a bound in `verify`
-  --> $DIR/type_mismatch.rs:22:14
+  --> $DIR/type_mismatch.rs:20:14
    |
 LL | fn verify<T: TheImportantOne>() {}
    |              ^^^^^^^^^^^^^^^ required by this bound in `verify`
diff --git a/tests/ui/diagnostic_namespace/do_not_recommend/type_mismatch.rs b/tests/ui/diagnostic_namespace/do_not_recommend/type_mismatch.rs
index d6721ccc848..7f30fdb06c7 100644
--- a/tests/ui/diagnostic_namespace/do_not_recommend/type_mismatch.rs
+++ b/tests/ui/diagnostic_namespace/do_not_recommend/type_mismatch.rs
@@ -2,8 +2,6 @@
 //@ ignore-compare-mode-next-solver (explicit revisions)
 //@[next] compile-flags: -Znext-solver
 
-#![feature(do_not_recommend)]
-
 #[diagnostic::on_unimplemented(message = "Very important message!")]
 trait TheImportantOne {}
 
diff --git a/tests/ui/diagnostic_namespace/do_not_recommend/unstable-feature.rs b/tests/ui/diagnostic_namespace/do_not_recommend/unstable-feature.rs
deleted file mode 100644
index ccc687aa5b3..00000000000
--- a/tests/ui/diagnostic_namespace/do_not_recommend/unstable-feature.rs
+++ /dev/null
@@ -1,8 +0,0 @@
-#![deny(unknown_or_malformed_diagnostic_attributes)]
-trait Foo {}
-
-#[diagnostic::do_not_recommend]
-//~^ ERROR unknown diagnostic attribute [unknown_or_malformed_diagnostic_attributes]
-impl Foo for i32 {}
-
-fn main() {}
diff --git a/tests/ui/diagnostic_namespace/do_not_recommend/unstable-feature.stderr b/tests/ui/diagnostic_namespace/do_not_recommend/unstable-feature.stderr
deleted file mode 100644
index d8332229d4f..00000000000
--- a/tests/ui/diagnostic_namespace/do_not_recommend/unstable-feature.stderr
+++ /dev/null
@@ -1,14 +0,0 @@
-error: unknown diagnostic attribute
-  --> $DIR/unstable-feature.rs:4:15
-   |
-LL | #[diagnostic::do_not_recommend]
-   |               ^^^^^^^^^^^^^^^^
-   |
-note: the lint level is defined here
-  --> $DIR/unstable-feature.rs:1:9
-   |
-LL | #![deny(unknown_or_malformed_diagnostic_attributes)]
-   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
-error: aborting due to 1 previous error
-
diff --git a/tests/ui/diagnostic_namespace/do_not_recommend/with_lifetime.current.stderr b/tests/ui/diagnostic_namespace/do_not_recommend/with_lifetime.current.stderr
new file mode 100644
index 00000000000..a8429ff60f8
--- /dev/null
+++ b/tests/ui/diagnostic_namespace/do_not_recommend/with_lifetime.current.stderr
@@ -0,0 +1,10 @@
+error: lifetime may not live long enough
+  --> $DIR/with_lifetime.rs:17:5
+   |
+LL | fn foo<'a>(a: &'a ()) {
+   |        -- lifetime `'a` defined here
+LL |     needs_root::<&'a ()>();
+   |     ^^^^^^^^^^^^^^^^^^^^ requires that `'a` must outlive `'static`
+
+error: aborting due to 1 previous error
+
diff --git a/tests/ui/diagnostic_namespace/do_not_recommend/with_lifetime.next.stderr b/tests/ui/diagnostic_namespace/do_not_recommend/with_lifetime.next.stderr
new file mode 100644
index 00000000000..a8429ff60f8
--- /dev/null
+++ b/tests/ui/diagnostic_namespace/do_not_recommend/with_lifetime.next.stderr
@@ -0,0 +1,10 @@
+error: lifetime may not live long enough
+  --> $DIR/with_lifetime.rs:17:5
+   |
+LL | fn foo<'a>(a: &'a ()) {
+   |        -- lifetime `'a` defined here
+LL |     needs_root::<&'a ()>();
+   |     ^^^^^^^^^^^^^^^^^^^^ requires that `'a` must outlive `'static`
+
+error: aborting due to 1 previous error
+
diff --git a/tests/ui/diagnostic_namespace/do_not_recommend/with_lifetime.rs b/tests/ui/diagnostic_namespace/do_not_recommend/with_lifetime.rs
new file mode 100644
index 00000000000..6a67d83d5fe
--- /dev/null
+++ b/tests/ui/diagnostic_namespace/do_not_recommend/with_lifetime.rs
@@ -0,0 +1,23 @@
+//@ revisions: current next
+//@ ignore-compare-mode-next-solver (explicit revisions)
+//@[next] compile-flags: -Znext-solver
+
+trait Root {}
+trait DontRecommend {}
+
+impl<T> Root for T where T: DontRecommend {}
+
+// this has no effect yet for resolving the trait error below
+#[diagnostic::do_not_recommend]
+impl<T> DontRecommend for &'static T {}
+
+fn needs_root<T: Root>() {}
+
+fn foo<'a>(a: &'a ()) {
+    needs_root::<&'a ()>();
+    //~^ ERROR lifetime may not live long enough
+}
+
+fn main() {
+    foo(&());
+}
diff --git a/tests/ui/feature-gates/feature-gate-multiple_supertrait_upcastable.stderr b/tests/ui/feature-gates/feature-gate-multiple_supertrait_upcastable.stderr
index 8a43d615963..0c7e68a599c 100644
--- a/tests/ui/feature-gates/feature-gate-multiple_supertrait_upcastable.stderr
+++ b/tests/ui/feature-gates/feature-gate-multiple_supertrait_upcastable.stderr
@@ -1,8 +1,8 @@
 warning: unknown lint: `multiple_supertrait_upcastable`
-  --> $DIR/feature-gate-multiple_supertrait_upcastable.rs:3:1
+  --> $DIR/feature-gate-multiple_supertrait_upcastable.rs:3:9
    |
 LL | #![deny(multiple_supertrait_upcastable)]
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: the `multiple_supertrait_upcastable` lint is unstable
    = help: add `#![feature(multiple_supertrait_upcastable)]` to the crate attributes to enable
@@ -10,10 +10,10 @@ LL | #![deny(multiple_supertrait_upcastable)]
    = note: `#[warn(unknown_lints)]` on by default
 
 warning: unknown lint: `multiple_supertrait_upcastable`
-  --> $DIR/feature-gate-multiple_supertrait_upcastable.rs:5:1
+  --> $DIR/feature-gate-multiple_supertrait_upcastable.rs:5:9
    |
 LL | #![warn(multiple_supertrait_upcastable)]
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: the `multiple_supertrait_upcastable` lint is unstable
    = help: add `#![feature(multiple_supertrait_upcastable)]` to the crate attributes to enable
diff --git a/tests/ui/feature-gates/feature-gate-non_exhaustive_omitted_patterns_lint.stderr b/tests/ui/feature-gates/feature-gate-non_exhaustive_omitted_patterns_lint.stderr
index 41764c8e018..7a453521590 100644
--- a/tests/ui/feature-gates/feature-gate-non_exhaustive_omitted_patterns_lint.stderr
+++ b/tests/ui/feature-gates/feature-gate-non_exhaustive_omitted_patterns_lint.stderr
@@ -1,8 +1,8 @@
 warning: unknown lint: `non_exhaustive_omitted_patterns`
-  --> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:3:1
+  --> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:3:9
    |
 LL | #![deny(non_exhaustive_omitted_patterns)]
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: the `non_exhaustive_omitted_patterns` lint is unstable
    = note: see issue #89554 <https://github.com/rust-lang/rust/issues/89554> for more information
@@ -11,10 +11,10 @@ LL | #![deny(non_exhaustive_omitted_patterns)]
    = note: `#[warn(unknown_lints)]` on by default
 
 warning: unknown lint: `non_exhaustive_omitted_patterns`
-  --> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:5:1
+  --> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:5:10
    |
 LL | #![allow(non_exhaustive_omitted_patterns)]
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: the `non_exhaustive_omitted_patterns` lint is unstable
    = note: see issue #89554 <https://github.com/rust-lang/rust/issues/89554> for more information
@@ -22,10 +22,10 @@ LL | #![allow(non_exhaustive_omitted_patterns)]
    = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
 
 warning: unknown lint: `non_exhaustive_omitted_patterns`
-  --> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:15:5
+  --> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:15:13
    |
 LL |     #[allow(non_exhaustive_omitted_patterns)]
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: the `non_exhaustive_omitted_patterns` lint is unstable
    = note: see issue #89554 <https://github.com/rust-lang/rust/issues/89554> for more information
@@ -33,10 +33,10 @@ LL |     #[allow(non_exhaustive_omitted_patterns)]
    = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
 
 warning: unknown lint: `non_exhaustive_omitted_patterns`
-  --> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:15:5
+  --> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:15:13
    |
 LL |     #[allow(non_exhaustive_omitted_patterns)]
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: the `non_exhaustive_omitted_patterns` lint is unstable
    = note: see issue #89554 <https://github.com/rust-lang/rust/issues/89554> for more information
@@ -45,10 +45,10 @@ LL |     #[allow(non_exhaustive_omitted_patterns)]
    = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
 
 warning: unknown lint: `non_exhaustive_omitted_patterns`
-  --> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:24:5
+  --> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:24:12
    |
 LL |     #[warn(non_exhaustive_omitted_patterns)]
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: the `non_exhaustive_omitted_patterns` lint is unstable
    = note: see issue #89554 <https://github.com/rust-lang/rust/issues/89554> for more information
@@ -56,10 +56,10 @@ LL |     #[warn(non_exhaustive_omitted_patterns)]
    = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
 
 warning: unknown lint: `non_exhaustive_omitted_patterns`
-  --> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:24:5
+  --> $DIR/feature-gate-non_exhaustive_omitted_patterns_lint.rs:24:12
    |
 LL |     #[warn(non_exhaustive_omitted_patterns)]
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: the `non_exhaustive_omitted_patterns` lint is unstable
    = note: see issue #89554 <https://github.com/rust-lang/rust/issues/89554> for more information
diff --git a/tests/ui/feature-gates/feature-gate-strict_provenance_lints.stderr b/tests/ui/feature-gates/feature-gate-strict_provenance_lints.stderr
index 15428cbd4be..3f3b49bc606 100644
--- a/tests/ui/feature-gates/feature-gate-strict_provenance_lints.stderr
+++ b/tests/ui/feature-gates/feature-gate-strict_provenance_lints.stderr
@@ -1,8 +1,8 @@
 warning: unknown lint: `fuzzy_provenance_casts`
-  --> $DIR/feature-gate-strict_provenance_lints.rs:3:1
+  --> $DIR/feature-gate-strict_provenance_lints.rs:3:9
    |
 LL | #![deny(fuzzy_provenance_casts)]
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |         ^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: the `fuzzy_provenance_casts` lint is unstable
    = note: see issue #130351 <https://github.com/rust-lang/rust/issues/130351> for more information
@@ -11,10 +11,10 @@ LL | #![deny(fuzzy_provenance_casts)]
    = note: `#[warn(unknown_lints)]` on by default
 
 warning: unknown lint: `lossy_provenance_casts`
-  --> $DIR/feature-gate-strict_provenance_lints.rs:5:1
+  --> $DIR/feature-gate-strict_provenance_lints.rs:5:9
    |
 LL | #![deny(lossy_provenance_casts)]
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |         ^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: the `lossy_provenance_casts` lint is unstable
    = note: see issue #130351 <https://github.com/rust-lang/rust/issues/130351> for more information
diff --git a/tests/ui/feature-gates/feature-gate-test_unstable_lint.stderr b/tests/ui/feature-gates/feature-gate-test_unstable_lint.stderr
index 5dc303da742..e460688e5fc 100644
--- a/tests/ui/feature-gates/feature-gate-test_unstable_lint.stderr
+++ b/tests/ui/feature-gates/feature-gate-test_unstable_lint.stderr
@@ -1,8 +1,8 @@
 warning: unknown lint: `test_unstable_lint`
-  --> $DIR/feature-gate-test_unstable_lint.rs:4:1
+  --> $DIR/feature-gate-test_unstable_lint.rs:4:10
    |
 LL | #![allow(test_unstable_lint)]
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |          ^^^^^^^^^^^^^^^^^^
    |
    = note: the `test_unstable_lint` lint is unstable
    = help: add `#![feature(test_unstable_lint)]` to the crate attributes to enable
diff --git a/tests/ui/feature-gates/feature-gate-unqualified-local-imports.stderr b/tests/ui/feature-gates/feature-gate-unqualified-local-imports.stderr
index 22cd3bf4c6f..bc8edd847cc 100644
--- a/tests/ui/feature-gates/feature-gate-unqualified-local-imports.stderr
+++ b/tests/ui/feature-gates/feature-gate-unqualified-local-imports.stderr
@@ -1,8 +1,8 @@
 warning: unknown lint: `unqualified_local_imports`
-  --> $DIR/feature-gate-unqualified-local-imports.rs:3:1
+  --> $DIR/feature-gate-unqualified-local-imports.rs:3:10
    |
 LL | #![allow(unqualified_local_imports)]
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |          ^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: the `unqualified_local_imports` lint is unstable
    = help: add `#![feature(unqualified_local_imports)]` to the crate attributes to enable
diff --git a/tests/ui/higher-ranked/trait-bounds/normalize-under-binder/norm-before-method-resolution-opaque-type.next.stderr b/tests/ui/higher-ranked/trait-bounds/normalize-under-binder/norm-before-method-resolution-opaque-type.next.stderr
deleted file mode 100644
index 9e04e90a98a..00000000000
--- a/tests/ui/higher-ranked/trait-bounds/normalize-under-binder/norm-before-method-resolution-opaque-type.next.stderr
+++ /dev/null
@@ -1,9 +0,0 @@
-error[E0284]: type annotations needed: cannot satisfy `Foo == _`
-  --> $DIR/norm-before-method-resolution-opaque-type.rs:15:19
-   |
-LL | fn weird_bound<X>(x: &<X as Trait<'static>>::Out<Foo>) -> X
-   |                   ^ cannot satisfy `Foo == _`
-
-error: aborting due to 1 previous error
-
-For more information about this error, try `rustc --explain E0284`.
diff --git a/tests/ui/higher-ranked/trait-bounds/normalize-under-binder/norm-before-method-resolution-opaque-type.old.stderr b/tests/ui/higher-ranked/trait-bounds/normalize-under-binder/norm-before-method-resolution-opaque-type.old.stderr
index 479f5984355..57cbe169118 100644
--- a/tests/ui/higher-ranked/trait-bounds/normalize-under-binder/norm-before-method-resolution-opaque-type.old.stderr
+++ b/tests/ui/higher-ranked/trait-bounds/normalize-under-binder/norm-before-method-resolution-opaque-type.old.stderr
@@ -1,12 +1,12 @@
 error: item does not constrain `Foo::{opaque#0}`, but has it in its signature
-  --> $DIR/norm-before-method-resolution-opaque-type.rs:15:4
+  --> $DIR/norm-before-method-resolution-opaque-type.rs:16:4
    |
 LL | fn weird_bound<X>(x: &<X as Trait<'static>>::Out<Foo>) -> X
    |    ^^^^^^^^^^^
    |
    = note: consider moving the opaque type's declaration and defining uses into a separate module
 note: this opaque type is in the signature
-  --> $DIR/norm-before-method-resolution-opaque-type.rs:13:12
+  --> $DIR/norm-before-method-resolution-opaque-type.rs:14:12
    |
 LL | type Foo = impl Sized;
    |            ^^^^^^^^^^
diff --git a/tests/ui/higher-ranked/trait-bounds/normalize-under-binder/norm-before-method-resolution-opaque-type.rs b/tests/ui/higher-ranked/trait-bounds/normalize-under-binder/norm-before-method-resolution-opaque-type.rs
index ffbfc622bb0..43207d89276 100644
--- a/tests/ui/higher-ranked/trait-bounds/normalize-under-binder/norm-before-method-resolution-opaque-type.rs
+++ b/tests/ui/higher-ranked/trait-bounds/normalize-under-binder/norm-before-method-resolution-opaque-type.rs
@@ -1,5 +1,6 @@
 //@ revisions: old next
 //@[next] compile-flags: -Znext-solver
+//@[next] check-pass
 
 #![feature(type_alias_impl_trait)]
 trait Trait<'a> {
@@ -14,7 +15,6 @@ type Foo = impl Sized;
 
 fn weird_bound<X>(x: &<X as Trait<'static>>::Out<Foo>) -> X
 //[old]~^ ERROR: item does not constrain
-//[next]~^^ ERROR: cannot satisfy `Foo == _`
 where
     for<'a> X: Trait<'a>,
     for<'a> <X as Trait<'a>>::Out<()>: Copy,
diff --git a/tests/ui/lint/must_not_suspend/gated.stderr b/tests/ui/lint/must_not_suspend/gated.stderr
index aff1b6a2ac4..8ec3202c5af 100644
--- a/tests/ui/lint/must_not_suspend/gated.stderr
+++ b/tests/ui/lint/must_not_suspend/gated.stderr
@@ -1,8 +1,8 @@
 warning: unknown lint: `must_not_suspend`
-  --> $DIR/gated.rs:4:1
+  --> $DIR/gated.rs:4:9
    |
 LL | #![deny(must_not_suspend)]
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |         ^^^^^^^^^^^^^^^^
    |
    = note: the `must_not_suspend` lint is unstable
    = note: see issue #83310 <https://github.com/rust-lang/rust/issues/83310> for more information
diff --git a/tests/ui/associated-path-shl.rs b/tests/ui/parser/associated-path-shl.rs
index 20a6fd83faa..20a6fd83faa 100644
--- a/tests/ui/associated-path-shl.rs
+++ b/tests/ui/parser/associated-path-shl.rs
diff --git a/tests/ui/associated-path-shl.stderr b/tests/ui/parser/associated-path-shl.stderr
index 71ee93f4835..71ee93f4835 100644
--- a/tests/ui/associated-path-shl.stderr
+++ b/tests/ui/parser/associated-path-shl.stderr
diff --git a/tests/ui/attrs-resolution-errors.rs b/tests/ui/resolve/attr-macros-positional-rejection.rs
index 8770fb1ded8..11382ff1399 100644
--- a/tests/ui/attrs-resolution-errors.rs
+++ b/tests/ui/resolve/attr-macros-positional-rejection.rs
@@ -1,3 +1,12 @@
+//! Check that certain positions (listed below) only permit *non-macro* attributes and reject
+//! attribute macros:
+//!
+//! - Enum variants
+//! - Struct fields
+//! - Field in a struct pattern
+//! - Match arm
+//! - Field in struct initialization expression
+
 enum FooEnum {
     #[test]
     //~^ ERROR expected non-macro attribute, found attribute macro
@@ -32,7 +41,7 @@ fn main() {
         _ => {}
     }
 
-    let _another_foo_strunct = FooStruct {
+    let _another_foo_struct = FooStruct {
         #[test]
         //~^ ERROR expected non-macro attribute, found attribute macro
         bar: 1,
diff --git a/tests/ui/attrs-resolution-errors.stderr b/tests/ui/resolve/attr-macros-positional-rejection.stderr
index 883f96e5c19..faea511f315 100644
--- a/tests/ui/attrs-resolution-errors.stderr
+++ b/tests/ui/resolve/attr-macros-positional-rejection.stderr
@@ -1,29 +1,29 @@
 error: expected non-macro attribute, found attribute macro `test`
-  --> $DIR/attrs-resolution-errors.rs:2:7
+  --> $DIR/attr-macros-positional-rejection.rs:11:7
    |
 LL |     #[test]
    |       ^^^^ not a non-macro attribute
 
 error: expected non-macro attribute, found attribute macro `test`
-  --> $DIR/attrs-resolution-errors.rs:8:7
+  --> $DIR/attr-macros-positional-rejection.rs:17:7
    |
 LL |     #[test]
    |       ^^^^ not a non-macro attribute
 
 error: expected non-macro attribute, found attribute macro `test`
-  --> $DIR/attrs-resolution-errors.rs:23:15
+  --> $DIR/attr-macros-positional-rejection.rs:32:15
    |
 LL |             #[test] bar
    |               ^^^^ not a non-macro attribute
 
 error: expected non-macro attribute, found attribute macro `test`
-  --> $DIR/attrs-resolution-errors.rs:30:11
+  --> $DIR/attr-macros-positional-rejection.rs:39:11
    |
 LL |         #[test]
    |           ^^^^ not a non-macro attribute
 
 error: expected non-macro attribute, found attribute macro `test`
-  --> $DIR/attrs-resolution-errors.rs:36:11
+  --> $DIR/attr-macros-positional-rejection.rs:45:11
    |
 LL |         #[test]
    |           ^^^^ not a non-macro attribute
diff --git a/tests/ui/attrs-resolution.rs b/tests/ui/resolve/non-macro-attrs-accepted.rs
index 38dd3812d68..76a04b2e837 100644
--- a/tests/ui/attrs-resolution.rs
+++ b/tests/ui/resolve/non-macro-attrs-accepted.rs
@@ -1,3 +1,11 @@
+//! Check that certain positions (listed below) permit *non-macro* attributes.
+//!
+//! - Enum variants
+//! - Struct fields
+//! - Field in a struct pattern
+//! - Match arm
+//! - Field in struct initialization expression
+
 //@ check-pass
 
 enum FooEnum {
@@ -30,7 +38,7 @@ fn main() {
         _ => {}
     }
 
-    let _another_foo_strunct = FooStruct {
+    let _another_foo_struct = FooStruct {
         #[rustfmt::skip]
         bar: 1,
     };
diff --git a/tests/ui/traits/next-solver/generalize/occurs-check-nested-alias.rs b/tests/ui/traits/next-solver/generalize/occurs-check-nested-alias.rs
index 00dc7a9d337..fbf4cadc678 100644
--- a/tests/ui/traits/next-solver/generalize/occurs-check-nested-alias.rs
+++ b/tests/ui/traits/next-solver/generalize/occurs-check-nested-alias.rs
@@ -37,9 +37,4 @@ fn foo<T: Unnormalizable>() {
     // result in a cyclic type. However, we can still unify these types by first
     // normalizing the inner associated type. Emitting an error here would be incomplete.
     drop::<T>(t);
-
-    // FIXME(-Znext-solver): This line is necessary due to an unrelated solver bug
-    // and should get removed in the future.
-    //   https://github.com/rust-lang/trait-system-refactor-initiative/issues/96
-    drop::<Inv<<T as Unnormalizable>::Assoc>>(u);
 }
diff --git a/tests/ui/traits/winnowing/global-non-global-env-1.rs b/tests/ui/traits/winnowing/global-non-global-env-1.rs
index d232d32dddf..75c184b65bf 100644
--- a/tests/ui/traits/winnowing/global-non-global-env-1.rs
+++ b/tests/ui/traits/winnowing/global-non-global-env-1.rs
@@ -1,3 +1,6 @@
+//@ revisions: current next
+//@ ignore-compare-mode-next-solver (explicit revisions)
+//@[next] compile-flags: -Znext-solver
 //@ check-pass
 
 // A regression test for an edge case of candidate selection
diff --git a/tests/ui/traits/winnowing/global-non-global-env-2.rs b/tests/ui/traits/winnowing/global-non-global-env-2.rs
index c73d0f06cd9..128ec2a40da 100644
--- a/tests/ui/traits/winnowing/global-non-global-env-2.rs
+++ b/tests/ui/traits/winnowing/global-non-global-env-2.rs
@@ -1,3 +1,6 @@
+//@ revisions: current next
+//@ ignore-compare-mode-next-solver (explicit revisions)
+//@[next] compile-flags: -Znext-solver
 //@ check-pass
 
 // A regression test for an edge case of candidate selection
diff --git a/tests/ui/traits/winnowing/global-non-global-env-3.rs b/tests/ui/traits/winnowing/global-non-global-env-3.rs
index 008d07e4144..7e5dbd4ba8e 100644
--- a/tests/ui/traits/winnowing/global-non-global-env-3.rs
+++ b/tests/ui/traits/winnowing/global-non-global-env-3.rs
@@ -1,3 +1,6 @@
+//@ revisions: current next
+//@ ignore-compare-mode-next-solver (explicit revisions)
+//@[next] compile-flags: -Znext-solver
 //@ check-pass
 
 // A regression test for an edge case of candidate selection
diff --git a/tests/ui/traits/winnowing/global-non-global-env-4.rs b/tests/ui/traits/winnowing/global-non-global-env-4.rs
index 74793620c9e..2dc082be45c 100644
--- a/tests/ui/traits/winnowing/global-non-global-env-4.rs
+++ b/tests/ui/traits/winnowing/global-non-global-env-4.rs
@@ -1,3 +1,6 @@
+//@ revisions: current next
+//@ ignore-compare-mode-next-solver (explicit revisions)
+//@[next] compile-flags: -Znext-solver
 //@ check-pass
 
 // A regression test for an edge case of candidate selection
diff --git a/tests/ui/attempted-access-non-fatal.rs b/tests/ui/typeck/attempted-access-non-fatal.rs
index 15deb9e2f60..15deb9e2f60 100644
--- a/tests/ui/attempted-access-non-fatal.rs
+++ b/tests/ui/typeck/attempted-access-non-fatal.rs
diff --git a/tests/ui/attempted-access-non-fatal.stderr b/tests/ui/typeck/attempted-access-non-fatal.stderr
index bff669727a1..bff669727a1 100644
--- a/tests/ui/attempted-access-non-fatal.stderr
+++ b/tests/ui/typeck/attempted-access-non-fatal.stderr
diff --git a/tests/ui/unknown-unstable-lints/deny-unstable-lint-inline.stderr b/tests/ui/unknown-unstable-lints/deny-unstable-lint-inline.stderr
index e486f04f273..4ff90945397 100644
--- a/tests/ui/unknown-unstable-lints/deny-unstable-lint-inline.stderr
+++ b/tests/ui/unknown-unstable-lints/deny-unstable-lint-inline.stderr
@@ -1,8 +1,8 @@
 error: unknown lint: `test_unstable_lint`
-  --> $DIR/deny-unstable-lint-inline.rs:4:1
+  --> $DIR/deny-unstable-lint-inline.rs:4:10
    |
 LL | #![allow(test_unstable_lint)]
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |          ^^^^^^^^^^^^^^^^^^
    |
    = note: the `test_unstable_lint` lint is unstable
    = help: add `#![feature(test_unstable_lint)]` to the crate attributes to enable
diff --git a/tests/ui/unknown-unstable-lints/warn-unknown-unstable-lint-inline.stderr b/tests/ui/unknown-unstable-lints/warn-unknown-unstable-lint-inline.stderr
index 981d3b1a874..7d56b360837 100644
--- a/tests/ui/unknown-unstable-lints/warn-unknown-unstable-lint-inline.stderr
+++ b/tests/ui/unknown-unstable-lints/warn-unknown-unstable-lint-inline.stderr
@@ -1,8 +1,8 @@
 warning: unknown lint: `test_unstable_lint`
-  --> $DIR/warn-unknown-unstable-lint-inline.rs:4:1
+  --> $DIR/warn-unknown-unstable-lint-inline.rs:4:10
    |
 LL | #![allow(test_unstable_lint)]
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |          ^^^^^^^^^^^^^^^^^^
    |
    = note: the `test_unstable_lint` lint is unstable
    = help: add `#![feature(test_unstable_lint)]` to the crate attributes to enable
diff --git a/triagebot.toml b/triagebot.toml
index 214fc2a21c4..eefb87aa298 100644
--- a/triagebot.toml
+++ b/triagebot.toml
@@ -996,6 +996,7 @@ contributing_url = "https://rustc-dev-guide.rust-lang.org/getting-started.html"
 users_on_vacation = [
     "jyn514",
     "celinval",
+    "nnethercote",
 ]
 
 [[assign.warn_non_default_branch.exceptions]]