Separate bounds and predicates for associated/opaque types

107 files changed, 934 insertions, 1128 deletions

diff --git a/compiler/rustc_ast_lowering/src/expr.rs b/compiler/rustc_ast_lowering/src/expr.rs
index c97f80cf09b..4676ad5c31f 100644
--- a/compiler/rustc_ast_lowering/src/expr.rs
+++ b/compiler/rustc_ast_lowering/src/expr.rs
@@ -432,17 +432,25 @@ impl<'hir> LoweringContext<'_, 'hir> {
         self.with_catch_scope(body.id, |this| {
             let mut block = this.lower_block_noalloc(body, true);
 
-            let try_span = this.mark_span_with_reason(
-                DesugaringKind::TryBlock,
-                body.span,
-                this.allow_try_trait.clone(),
-            );
-
             // Final expression of the block (if present) or `()` with span at the end of block
-            let tail_expr = block
-                .expr
-                .take()
-                .unwrap_or_else(|| this.expr_unit(this.sess.source_map().end_point(try_span)));
+            let (try_span, tail_expr) = if let Some(expr) = block.expr.take() {
+                (
+                    this.mark_span_with_reason(
+                        DesugaringKind::TryBlock,
+                        expr.span,
+                        this.allow_try_trait.clone(),
+                    ),
+                    expr,
+                )
+            } else {
+                let try_span = this.mark_span_with_reason(
+                    DesugaringKind::TryBlock,
+                    this.sess.source_map().end_point(body.span),
+                    this.allow_try_trait.clone(),
+                );
+
+                (try_span, this.expr_unit(try_span))
+            };
 
             let ok_wrapped_span =
                 this.mark_span_with_reason(DesugaringKind::TryBlock, tail_expr.span, None);
@@ -1553,7 +1561,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
                 hir::LangItem::TryFromError,
                 unstable_span,
                 from_expr,
-                try_span,
+                unstable_span,
             );
             let thin_attrs = ThinVec::from(attrs);
             let catch_scope = self.catch_scopes.last().copied();
diff --git a/compiler/rustc_infer/src/traits/util.rs b/compiler/rustc_infer/src/traits/util.rs
index 9c0d934a035..1b7269706a7 100644
--- a/compiler/rustc_infer/src/traits/util.rs
+++ b/compiler/rustc_infer/src/traits/util.rs
@@ -4,7 +4,6 @@ use crate::traits::{Obligation, ObligationCause, PredicateObligation};
 use rustc_data_structures::fx::FxHashSet;
 use rustc_middle::ty::outlives::Component;
 use rustc_middle::ty::{self, ToPredicate, TyCtxt, WithConstness};
-use rustc_span::Span;
 
 pub fn anonymize_predicate<'tcx>(
     tcx: TyCtxt<'tcx>,
@@ -94,7 +93,11 @@ pub fn elaborate_predicates<'tcx>(
     tcx: TyCtxt<'tcx>,
     predicates: impl Iterator<Item = ty::Predicate<'tcx>>,
 ) -> Elaborator<'tcx> {
-    let obligations = predicates.map(|predicate| predicate_obligation(predicate, None)).collect();
+    let obligations = predicates
+        .map(|predicate| {
+            predicate_obligation(predicate, ty::ParamEnv::empty(), ObligationCause::dummy())
+        })
+        .collect();
     elaborate_obligations(tcx, obligations)
 }
 
@@ -109,15 +112,10 @@ pub fn elaborate_obligations<'tcx>(
 
 fn predicate_obligation<'tcx>(
     predicate: ty::Predicate<'tcx>,
-    span: Option<Span>,
+    param_env: ty::ParamEnv<'tcx>,
+    cause: ObligationCause<'tcx>,
 ) -> PredicateObligation<'tcx> {
-    let cause = if let Some(span) = span {
-        ObligationCause::dummy_with_span(span)
-    } else {
-        ObligationCause::dummy()
-    };
-
-    Obligation { cause, param_env: ty::ParamEnv::empty(), recursion_depth: 0, predicate }
+    Obligation { cause, param_env, recursion_depth: 0, predicate }
 }
 
 impl Elaborator<'tcx> {
@@ -133,10 +131,11 @@ impl Elaborator<'tcx> {
                 // Get predicates declared on the trait.
                 let predicates = tcx.super_predicates_of(data.def_id());
 
-                let obligations = predicates.predicates.iter().map(|&(pred, span)| {
+                let obligations = predicates.predicates.iter().map(|&(pred, _)| {
                     predicate_obligation(
                         pred.subst_supertrait(tcx, &ty::Binder::bind(data.trait_ref)),
-                        Some(span),
+                        obligation.param_env,
+                        obligation.cause.clone(),
                     )
                 });
                 debug!("super_predicates: data={:?}", data);
@@ -233,7 +232,13 @@ impl Elaborator<'tcx> {
                         })
                         .map(|predicate_kind| predicate_kind.to_predicate(tcx))
                         .filter(|&predicate| visited.insert(predicate))
-                        .map(|predicate| predicate_obligation(predicate, None)),
+                        .map(|predicate| {
+                            predicate_obligation(
+                                predicate,
+                                obligation.param_env,
+                                obligation.cause.clone(),
+                            )
+                        }),
                 );
             }
             ty::PredicateAtom::TypeWellFormedFromEnv(..) => {
diff --git a/compiler/rustc_lint/src/unused.rs b/compiler/rustc_lint/src/unused.rs
index 1e8c30071e7..3abd9a6325d 100644
--- a/compiler/rustc_lint/src/unused.rs
+++ b/compiler/rustc_lint/src/unused.rs
@@ -200,7 +200,7 @@ impl<'tcx> LateLintPass<'tcx> for UnusedResults {
                 ty::Adt(def, _) => check_must_use_def(cx, def.did, span, descr_pre, descr_post),
                 ty::Opaque(def, _) => {
                     let mut has_emitted = false;
-                    for (predicate, _) in cx.tcx.predicates_of(def).predicates {
+                    for &(predicate, _) in cx.tcx.explicit_item_bounds(def) {
                         // We only look at the `DefId`, so it is safe to skip the binder here.
                         if let ty::PredicateAtom::Trait(ref poly_trait_predicate, _) =
                             predicate.skip_binders()
diff --git a/compiler/rustc_metadata/src/rmeta/encoder.rs b/compiler/rustc_metadata/src/rmeta/encoder.rs
index 9f12edf9cb2..f0911928e81 100644
--- a/compiler/rustc_metadata/src/rmeta/encoder.rs
+++ b/compiler/rustc_metadata/src/rmeta/encoder.rs
@@ -1266,7 +1266,10 @@ impl EncodeContext<'a, 'tcx> {
             hir::ItemKind::ForeignMod(_) => EntryKind::ForeignMod,
             hir::ItemKind::GlobalAsm(..) => EntryKind::GlobalAsm,
             hir::ItemKind::TyAlias(..) => EntryKind::Type,
-            hir::ItemKind::OpaqueTy(..) => EntryKind::OpaqueTy,
+            hir::ItemKind::OpaqueTy(..) => {
+                self.encode_explicit_item_bounds(def_id);
+                EntryKind::OpaqueTy
+            }
             hir::ItemKind::Enum(..) => EntryKind::Enum(self.tcx.adt_def(def_id).repr),
             hir::ItemKind::Struct(ref struct_def, _) => {
                 let adt_def = self.tcx.adt_def(def_id);
diff --git a/compiler/rustc_middle/src/ty/print/pretty.rs b/compiler/rustc_middle/src/ty/print/pretty.rs
index 5cd8f3e7877..e1f02d0f704 100644
--- a/compiler/rustc_middle/src/ty/print/pretty.rs
+++ b/compiler/rustc_middle/src/ty/print/pretty.rs
@@ -607,12 +607,13 @@ pub trait PrettyPrinter<'tcx>:
                     }
                     // Grab the "TraitA + TraitB" from `impl TraitA + TraitB`,
                     // by looking up the projections associated with the def_id.
-                    let bounds = self.tcx().item_bounds(def_id).subst(self.tcx(), substs);
+                    let bounds = self.tcx().explicit_item_bounds(def_id);
 
                     let mut first = true;
                     let mut is_sized = false;
                     p!("impl");
-                    for predicate in bounds {
+                    for (predicate, _) in bounds {
+                        let predicate = predicate.subst(self.tcx(), substs);
                         // Note: We can't use `to_opt_poly_trait_ref` here as `predicate`
                         // may contain unbound variables. We therefore do this manually.
                         //
diff --git a/compiler/rustc_privacy/src/lib.rs b/compiler/rustc_privacy/src/lib.rs
index 8d1b826ea35..8f93bce6e99 100644
--- a/compiler/rustc_privacy/src/lib.rs
+++ b/compiler/rustc_privacy/src/lib.rs
@@ -194,11 +194,14 @@ where
                     // The intent is to treat `impl Trait1 + Trait2` identically to
                     // `dyn Trait1 + Trait2`. Therefore we ignore def-id of the opaque type itself
                     // (it either has no visibility, or its visibility is insignificant, like
-                    // visibilities of type aliases) and recurse into predicates instead to go
+                    // visibilities of type aliases) and recurse into bounds instead to go
                     // through the trait list (default type visitor doesn't visit those traits).
                     // All traits in the list are considered the "primary" part of the type
                     // and are visited by shallow visitors.
-                    if self.visit_predicates(tcx.predicates_of(def_id)) {
+                    if self.visit_predicates(ty::GenericPredicates {
+                        parent: None,
+                        predicates: tcx.explicit_item_bounds(def_id),
+                    }) {
                         return true;
                     }
                 }
@@ -1800,6 +1803,14 @@ impl SearchInterfaceForPrivateItemsVisitor<'tcx> {
         self
     }
 
+    fn bounds(&mut self) -> &mut Self {
+        self.visit_predicates(ty::GenericPredicates {
+            parent: None,
+            predicates: self.tcx.explicit_item_bounds(self.item_def_id),
+        });
+        self
+    }
+
     fn ty(&mut self) -> &mut Self {
         self.visit(self.tcx.type_of(self.item_def_id));
         self
@@ -1975,7 +1986,7 @@ impl<'a, 'tcx> Visitor<'tcx> for PrivateItemsInPublicInterfacesVisitor<'a, 'tcx>
             hir::ItemKind::OpaqueTy(..) => {
                 // `ty()` for opaque types is the underlying type,
                 // it's not a part of interface, so we skip it.
-                self.check(item.hir_id, item_visibility).generics().predicates();
+                self.check(item.hir_id, item_visibility).generics().bounds();
             }
             hir::ItemKind::Trait(.., trait_item_refs) => {
                 self.check(item.hir_id, item_visibility).generics().predicates();
@@ -1987,6 +1998,10 @@ impl<'a, 'tcx> Visitor<'tcx> for PrivateItemsInPublicInterfacesVisitor<'a, 'tcx>
                         trait_item_ref.defaultness,
                         item_visibility,
                     );
+
+                    if let AssocItemKind::Type = trait_item_ref.kind {
+                        self.check(trait_item_ref.id.hir_id, item_visibility).bounds();
+                    }
                 }
             }
             hir::ItemKind::TraitAlias(..) => {
diff --git a/compiler/rustc_traits/src/chalk/db.rs b/compiler/rustc_traits/src/chalk/db.rs
index 828ee6dea62..35b1064d2e4 100644
--- a/compiler/rustc_traits/src/chalk/db.rs
+++ b/compiler/rustc_traits/src/chalk/db.rs
@@ -73,18 +73,28 @@ impl<'tcx> chalk_solve::RustIrDatabase<RustInterner<'tcx>> for RustIrDatabase<'t
         }
         let bound_vars = bound_vars_for_item(self.interner.tcx, def_id);
         let binders = binders_for(&self.interner, bound_vars);
-        // FIXME(chalk): this really isn't right I don't think. The functions
-        // for GATs are a bit hard to figure out. Are these supposed to be where
-        // clauses or bounds?
+
         let where_clauses = self.where_clauses_for(def_id, bound_vars);
 
+        let bounds = self
+            .tcx
+            .explicit_item_bounds(def_id)
+            .iter()
+            .map(|(bound, _)| bound.subst(self.tcx, &bound_vars))
+            .filter_map(|bound| {
+                LowerInto::<
+                        Option<chalk_solve::rust_ir::QuantifiedInlineBound<RustInterner<'tcx>>>,
+                    >::lower_into(bound, &self.interner)
+            })
+            .collect();
+
         Arc::new(chalk_solve::rust_ir::AssociatedTyDatum {
             trait_id: chalk_ir::TraitId(trait_def_id),
             id: assoc_type_id,
             name: (),
             binders: chalk_ir::Binders::new(
                 binders,
-                chalk_solve::rust_ir::AssociatedTyDatumBound { bounds: vec![], where_clauses },
+                chalk_solve::rust_ir::AssociatedTyDatumBound { bounds, where_clauses },
             ),
         })
     }
@@ -443,10 +453,17 @@ impl<'tcx> chalk_solve::RustIrDatabase<RustInterner<'tcx>> for RustIrDatabase<'t
         let binders = binders_for(&self.interner, bound_vars);
         let where_clauses = self.where_clauses_for(opaque_ty_id.0, bound_vars);
 
+        let bounds: Vec<_> = predicates
+            .iter()
+            .map(|(bound, _)| bound.subst(self.tcx, &bound_vars))
+            .filter_map(|bound| LowerInto::<Option<chalk_ir::QuantifiedWhereClause<RustInterner<'tcx>>>>::lower_into(bound, &self.interner))
+            .collect();
+
         let value = chalk_solve::rust_ir::OpaqueTyDatumBound {
-            bounds: chalk_ir::Binders::new(binders.clone(), vec![]),
+            bounds: chalk_ir::Binders::new(binders, bounds),
             where_clauses: chalk_ir::Binders::new(binders, where_clauses),
         };
+
         Arc::new(chalk_solve::rust_ir::OpaqueTyDatum {
             opaque_ty_id,
             bound: chalk_ir::Binders::empty(&self.interner, value),
diff --git a/compiler/rustc_traits/src/chalk/lowering.rs b/compiler/rustc_traits/src/chalk/lowering.rs
index 1e1841a57f8..0602f5ea4dc 100644
--- a/compiler/rustc_traits/src/chalk/lowering.rs
+++ b/compiler/rustc_traits/src/chalk/lowering.rs
@@ -728,6 +728,84 @@ impl<'tcx> LowerInto<'tcx, chalk_ir::FnSig<RustInterner<'tcx>>> for ty::Binder<t
     }
 }
 
+// We lower into an Option here since there are some predicates which Chalk
+// doesn't have a representation for yet (as an `InlineBound`). The `Option` will
+// eventually be removed.
+impl<'tcx> LowerInto<'tcx, Option<chalk_solve::rust_ir::QuantifiedInlineBound<RustInterner<'tcx>>>>
+    for ty::Predicate<'tcx>
+{
+    fn lower_into(
+        self,
+        interner: &RustInterner<'tcx>,
+    ) -> Option<chalk_solve::rust_ir::QuantifiedInlineBound<RustInterner<'tcx>>> {
+        match &self.kind() {
+            ty::PredicateKind::Trait(predicate, _) => {
+                let (predicate, binders, _named_regions) =
+                    collect_bound_vars(interner, interner.tcx, predicate);
+
+                Some(chalk_ir::Binders::new(
+                    binders,
+                    chalk_solve::rust_ir::InlineBound::TraitBound(
+                        predicate.trait_ref.lower_into(interner),
+                    ),
+                ))
+            }
+            ty::PredicateKind::Projection(predicate) => {
+                let (predicate, binders, _named_regions) =
+                    collect_bound_vars(interner, interner.tcx, predicate);
+
+                Some(chalk_ir::Binders::new(
+                    binders,
+                    chalk_solve::rust_ir::InlineBound::AliasEqBound(predicate.lower_into(interner)),
+                ))
+            }
+            ty::PredicateKind::TypeOutlives(_predicate) => None,
+            ty::PredicateKind::WellFormed(_ty) => None,
+
+            ty::PredicateKind::RegionOutlives(..)
+            | ty::PredicateKind::ObjectSafe(..)
+            | ty::PredicateKind::ClosureKind(..)
+            | ty::PredicateKind::Subtype(..)
+            | ty::PredicateKind::ConstEvaluatable(..)
+            | ty::PredicateKind::ConstEquate(..) => bug!("unexpected predicate {}", &self),
+        }
+    }
+}
+
+impl<'tcx> LowerInto<'tcx, chalk_solve::rust_ir::TraitBound<RustInterner<'tcx>>>
+    for ty::TraitRef<'tcx>
+{
+    fn lower_into(
+        self,
+        interner: &RustInterner<'tcx>,
+    ) -> chalk_solve::rust_ir::TraitBound<RustInterner<'tcx>> {
+        chalk_solve::rust_ir::TraitBound {
+            trait_id: chalk_ir::TraitId(self.def_id),
+            args_no_self: self.substs[1..].iter().map(|arg| arg.lower_into(interner)).collect(),
+        }
+    }
+}
+
+impl<'tcx> LowerInto<'tcx, chalk_solve::rust_ir::AliasEqBound<RustInterner<'tcx>>>
+    for ty::ProjectionPredicate<'tcx>
+{
+    fn lower_into(
+        self,
+        interner: &RustInterner<'tcx>,
+    ) -> chalk_solve::rust_ir::AliasEqBound<RustInterner<'tcx>> {
+        let trait_ref = self.projection_ty.trait_ref(interner.tcx);
+        chalk_solve::rust_ir::AliasEqBound {
+            trait_bound: trait_ref.lower_into(interner),
+            associated_ty_id: chalk_ir::AssocTypeId(self.projection_ty.item_def_id),
+            parameters: self.projection_ty.substs[trait_ref.substs.len()..]
+                .iter()
+                .map(|arg| arg.lower_into(interner))
+                .collect(),
+            value: self.ty.lower_into(interner),
+        }
+    }
+}
+
 /// To collect bound vars, we have to do two passes. In the first pass, we
 /// collect all `BoundRegion`s and `ty::Bound`s. In the second pass, we then
 /// replace `BrNamed` into `BrAnon`. The two separate passes are important,
diff --git a/compiler/rustc_typeck/src/check/check.rs b/compiler/rustc_typeck/src/check/check.rs
index 0647be2dfde..2df9007195f 100644
--- a/compiler/rustc_typeck/src/check/check.rs
+++ b/compiler/rustc_typeck/src/check/check.rs
@@ -1,4 +1,5 @@
 use super::coercion::CoerceMany;
+use super::compare_method::check_type_bounds;
 use super::compare_method::{compare_const_impl, compare_impl_method, compare_ty_impl};
 use super::*;
 
@@ -453,8 +454,7 @@ pub(super) fn check_opaque_for_inheriting_lifetimes(
             ty: None,
         };
         let prohibit_opaque = tcx
-            .predicates_of(def_id)
-            .predicates
+            .explicit_item_bounds(def_id)
             .iter()
             .any(|(predicate, _)| predicate.visit_with(&mut visitor));
         debug!(
@@ -476,7 +476,7 @@ pub(super) fn check_opaque_for_inheriting_lifetimes(
                 span,
                 E0760,
                 "`{}` return type cannot contain a projection or `Self` that references lifetimes from \
-             a parent scope",
+                 a parent scope",
                 if is_async { "async fn" } else { "impl Trait" },
             );
 
@@ -553,9 +553,25 @@ pub fn check_item_type<'tcx>(tcx: TyCtxt<'tcx>, it: &'tcx hir::Item<'tcx>) {
 
             for item in items.iter() {
                 let item = tcx.hir().trait_item(item.id);
-                if let hir::TraitItemKind::Fn(sig, _) = &item.kind {
-                    let abi = sig.header.abi;
-                    fn_maybe_err(tcx, item.ident.span, abi);
+                match item.kind {
+                    hir::TraitItemKind::Fn(ref sig, _) => {
+                        let abi = sig.header.abi;
+                        fn_maybe_err(tcx, item.ident.span, abi);
+                    }
+                    hir::TraitItemKind::Type(.., Some(_default)) => {
+                        let item_def_id = tcx.hir().local_def_id(item.hir_id).to_def_id();
+                        let assoc_item = tcx.associated_item(item_def_id);
+                        let trait_substs =
+                            InternalSubsts::identity_for_item(tcx, def_id.to_def_id());
+                        let _: Result<_, rustc_errors::ErrorReported> = check_type_bounds(
+                            tcx,
+                            assoc_item,
+                            assoc_item,
+                            item.span,
+                            ty::TraitRef { def_id: def_id.to_def_id(), substs: trait_substs },
+                        );
+                    }
+                    _ => {}
                 }
             }
         }
diff --git a/compiler/rustc_typeck/src/check/compare_method.rs b/compiler/rustc_typeck/src/check/compare_method.rs
index 8111a0bad9f..3515fb12e4c 100644
--- a/compiler/rustc_typeck/src/check/compare_method.rs
+++ b/compiler/rustc_typeck/src/check/compare_method.rs
@@ -5,6 +5,7 @@ use rustc_hir::def::{DefKind, Res};
 use rustc_hir::intravisit;
 use rustc_hir::{GenericParamKind, ImplItemKind, TraitItemKind};
 use rustc_infer::infer::{self, InferOk, TyCtxtInferExt};
+use rustc_infer::traits::util;
 use rustc_middle::ty;
 use rustc_middle::ty::error::{ExpectedFound, TypeError};
 use rustc_middle::ty::subst::{InternalSubsts, Subst};
@@ -1170,20 +1171,13 @@ fn compare_type_predicate_entailment<'tcx>(
 /// For default associated types the normalization is not possible (the value
 /// from the impl could be overridden). We also can't normalize generic
 /// associated types (yet) because they contain bound parameters.
-fn check_type_bounds<'tcx>(
+pub fn check_type_bounds<'tcx>(
     tcx: TyCtxt<'tcx>,
     trait_ty: &ty::AssocItem,
     impl_ty: &ty::AssocItem,
     impl_ty_span: Span,
     impl_trait_ref: ty::TraitRef<'tcx>,
 ) -> Result<(), ErrorReported> {
-    let have_gats = tcx.features().generic_associated_types;
-    if impl_ty.defaultness.is_final() && !have_gats {
-        // For "final", non-generic associate type implementations, we
-        // don't need this as described above.
-        return Ok(());
-    }
-
     // Given
     //
     // impl<A, B> Foo<u32> for (A, B) {
@@ -1237,10 +1231,20 @@ fn check_type_bounds<'tcx>(
             ObligationCauseCode::ItemObligation(trait_ty.def_id),
         );
 
-        let predicates = tcx.item_bounds(trait_ty.def_id);
-        debug!("check_type_bounds: item_bounds={:?}", predicates);
+        let obligations = tcx
+            .explicit_item_bounds(trait_ty.def_id)
+            .iter()
+            .map(|&(bound, span)| {
+                let concrete_ty_bound =
+                    traits::subst_assoc_item_bound(tcx, bound, impl_ty_value, rebased_substs);
+                debug!("check_type_bounds: concrete_ty_bound = {:?}", concrete_ty_bound);
 
-        for predicate in predicates {
+                traits::Obligation::new(mk_cause(span), param_env, concrete_ty_bound)
+            })
+            .collect();
+        debug!("check_type_bounds: item_bounds={:?}", obligations);
+
+        for obligation in util::elaborate_obligations(tcx, obligations) {
             let concrete_ty_predicate = predicate.subst(tcx, rebased_substs);
             debug!("compare_projection_bounds: concrete predicate = {:?}", concrete_ty_predicate);
 
@@ -1252,12 +1256,7 @@ fn check_type_bounds<'tcx>(
             );
             debug!("compare_projection_bounds: normalized predicate = {:?}", normalized_predicate);
 
-            inh.register_predicates(obligations);
-            inh.register_predicate(traits::Obligation::new(
-                cause.clone(),
-                param_env,
-                normalized_predicate,
-            ));
+            inh.register_predicate(obligation);
         }
 
         // Check that all obligations are satisfied by the implementation's
diff --git a/compiler/rustc_typeck/src/check/wfcheck.rs b/compiler/rustc_typeck/src/check/wfcheck.rs
index 5203f3fa8f1..f31ba886d52 100644
--- a/compiler/rustc_typeck/src/check/wfcheck.rs
+++ b/compiler/rustc_typeck/src/check/wfcheck.rs
@@ -420,6 +420,9 @@ fn check_associated_item(
                 check_method_receiver(fcx, hir_sig, &item, self_ty);
             }
             ty::AssocKind::Type => {
+                if let ty::AssocItemContainer::TraitContainer(_) = item.container {
+                    check_associated_type_bounds(fcx, item, span)
+                }
                 if item.defaultness.has_value() {
                     let ty = fcx.tcx.type_of(item.def_id);
                     let ty = fcx.normalize_associated_types_in(span, &ty);
@@ -571,7 +574,6 @@ fn check_trait(tcx: TyCtxt<'_>, item: &hir::Item<'_>) {
 
     for_item(tcx, item).with_fcx(|fcx, _| {
         check_where_clauses(tcx, fcx, item.span, trait_def_id.to_def_id(), None);
-        check_associated_type_defaults(fcx, trait_def_id.to_def_id());
 
         vec![]
     });
@@ -581,96 +583,26 @@ fn check_trait(tcx: TyCtxt<'_>, item: &hir::Item<'_>) {
 ///
 /// Assuming the defaults are used, check that all predicates (bounds on the
 /// assoc type and where clauses on the trait) hold.
-fn check_associated_type_defaults(fcx: &FnCtxt<'_, '_>, trait_def_id: DefId) {
+fn check_associated_type_bounds(fcx: &FnCtxt<'_, '_>, item: &ty::AssocItem, span: Span) {
     let tcx = fcx.tcx;
-    let substs = InternalSubsts::identity_for_item(tcx, trait_def_id);
-
-    // For all assoc. types with defaults, build a map from
-    // `<Self as Trait<...>>::Assoc` to the default type.
-    let map = tcx
-        .associated_items(trait_def_id)
-        .in_definition_order()
-        .filter_map(|item| {
-            if item.kind == ty::AssocKind::Type && item.defaultness.has_value() {
-                // `<Self as Trait<...>>::Assoc`
-                let proj = ty::ProjectionTy { substs, item_def_id: item.def_id };
-                let default_ty = tcx.type_of(item.def_id);
-                debug!("assoc. type default mapping: {} -> {}", proj, default_ty);
-                Some((proj, default_ty))
-            } else {
-                None
-            }
-        })
-        .collect::<FxHashMap<_, _>>();
-
-    /// Replaces projections of associated types with their default types.
-    ///
-    /// This does a "shallow substitution", meaning that defaults that refer to
-    /// other defaulted assoc. types will still refer to the projection
-    /// afterwards, not to the other default. For example:
-    ///
-    /// ```compile_fail
-    /// trait Tr {
-    ///     type A: Clone = Vec<Self::B>;
-    ///     type B = u8;
-    /// }
-    /// ```
-    ///
-    /// This will end up replacing the bound `Self::A: Clone` with
-    /// `Vec<Self::B>: Clone`, not with `Vec<u8>: Clone`. If we did a deep
-    /// substitution and ended up with the latter, the trait would be accepted.
-    /// If an `impl` then replaced `B` with something that isn't `Clone`,
-    /// suddenly the default for `A` is no longer valid. The shallow
-    /// substitution forces the trait to add a `B: Clone` bound to be accepted,
-    /// which means that an `impl` can replace any default without breaking
-    /// others.
-    ///
-    /// Note that this isn't needed for soundness: The defaults would still be
-    /// checked in any impl that doesn't override them.
-    struct DefaultNormalizer<'tcx> {
-        tcx: TyCtxt<'tcx>,
-        map: FxHashMap<ty::ProjectionTy<'tcx>, Ty<'tcx>>,
-    }
 
-    impl<'tcx> ty::fold::TypeFolder<'tcx> for DefaultNormalizer<'tcx> {
-        fn tcx<'a>(&'a self) -> TyCtxt<'tcx> {
-            self.tcx
-        }
+    let bounds = tcx.explicit_item_bounds(item.def_id);
 
-        fn fold_ty(&mut self, t: Ty<'tcx>) -> Ty<'tcx> {
-            match t.kind() {
-                ty::Projection(proj_ty) => {
-                    if let Some(default) = self.map.get(&proj_ty) {
-                        default
-                    } else {
-                        t.super_fold_with(self)
-                    }
-                }
-                _ => t.super_fold_with(self),
-            }
-        }
-    }
-
-    // Now take all predicates defined on the trait, replace any mention of
-    // the assoc. types with their default, and prove them.
-    // We only consider predicates that directly mention the assoc. type.
-    let mut norm = DefaultNormalizer { tcx, map };
-    let predicates = fcx.tcx.predicates_of(trait_def_id);
-    for &(orig_pred, span) in predicates.predicates.iter() {
-        let pred = orig_pred.fold_with(&mut norm);
-        if pred != orig_pred {
-            // Mentions one of the defaulted assoc. types
-            debug!("default suitability check: proving predicate: {} -> {}", orig_pred, pred);
-            let pred = fcx.normalize_associated_types_in(span, &pred);
-            let cause = traits::ObligationCause::new(
-                span,
-                fcx.body_id,
-                traits::ItemObligation(trait_def_id),
-            );
-            let obligation = traits::Obligation::new(cause, fcx.param_env, pred);
+    debug!("check_associated_type_bounds: bounds={:?}", bounds);
+    let wf_obligations = bounds.iter().flat_map(|&(bound, bound_span)| {
+        let normalized_bound = fcx.normalize_associated_types_in(span, &bound);
+        traits::wf::predicate_obligations(
+            fcx,
+            fcx.param_env,
+            fcx.body_id,
+            normalized_bound,
+            bound_span,
+        )
+    });
 
-            fcx.register_predicate(obligation);
-        }
+    for obligation in wf_obligations {
+        debug!("next obligation cause: {:?}", obligation.cause);
+        fcx.register_predicate(obligation);
     }
 }
 
diff --git a/compiler/rustc_typeck/src/collect.rs b/compiler/rustc_typeck/src/collect.rs
index 4df5135cca5..737bc3a753d 100644
--- a/compiler/rustc_typeck/src/collect.rs
+++ b/compiler/rustc_typeck/src/collect.rs
@@ -711,8 +711,10 @@ fn convert_item(tcx: TyCtxt<'_>, item_id: hir::HirId) {
             tcx.ensure().generics_of(def_id);
             tcx.ensure().type_of(def_id);
             tcx.ensure().predicates_of(def_id);
-            if let hir::ItemKind::Fn(..) = it.kind {
-                tcx.ensure().fn_sig(def_id);
+            match it.kind {
+                hir::ItemKind::Fn(..) => tcx.ensure().fn_sig(def_id),
+                hir::ItemKind::OpaqueTy(..) => tcx.ensure().item_bounds(def_id),
+                _ => (),
             }
         }
     }
@@ -733,15 +735,25 @@ fn convert_trait_item(tcx: TyCtxt<'_>, trait_item_id: hir::HirId) {
             tcx.ensure().type_of(def_id);
         }
 
-        hir::TraitItemKind::Const(..) | hir::TraitItemKind::Type(_, Some(_)) => {
+        hir::TraitItemKind::Const(..) => {
             tcx.ensure().type_of(def_id);
-            // Account for `const C: _;` and `type T = _;`.
+            // Account for `const C: _;`.
+            let mut visitor = PlaceholderHirTyCollector::default();
+            visitor.visit_trait_item(trait_item);
+            placeholder_type_error(tcx, None, &[], visitor.0, false);
+        }
+
+        hir::TraitItemKind::Type(_, Some(_)) => {
+            tcx.ensure().item_bounds(def_id);
+            tcx.ensure().type_of(def_id);
+            // Account for `type T = _;`.
             let mut visitor = PlaceholderHirTyCollector::default();
             visitor.visit_trait_item(trait_item);
             placeholder_type_error(tcx, None, &[], visitor.0, false);
         }
 
         hir::TraitItemKind::Type(_, None) => {
+            tcx.ensure().item_bounds(def_id);
             // #74612: Visit and try to find bad placeholders
             // even if there is no concrete type.
             let mut visitor = PlaceholderHirTyCollector::default();
diff --git a/src/test/ui/associated-type-bounds/bad-bounds-on-assoc-in-trait.rs b/src/test/ui/associated-type-bounds/bad-bounds-on-assoc-in-trait.rs
index 556d8900d1a..4c78f17a6a3 100644
--- a/src/test/ui/associated-type-bounds/bad-bounds-on-assoc-in-trait.rs
+++ b/src/test/ui/associated-type-bounds/bad-bounds-on-assoc-in-trait.rs
@@ -23,19 +23,17 @@ trait Case1 {
                 Debug
             >
         > + Sync>;
+        //~^^^^^^ ERROR `<<Self as Case1>::C as std::iter::Iterator>::Item` is not an iterator
+        //~^^^^^^ ERROR `<<Self as Case1>::C as std::iter::Iterator>::Item` cannot be sent between threads safely
+        //~^^^ ERROR `<<Self as Case1>::C as std::iter::Iterator>::Item` cannot be shared between threads safely
 }
 
 pub struct S1;
 impl Case1 for S1 {
-//~^ ERROR `<L1 as Lam<&'a u8>>::App` doesn't implement `Debug` [E0277]
     type C = Once<Once<L1>>;
 }
 
 fn assume_case1<T: Case1>() {
-//~^ ERROR `<_ as Lam<&'a u8>>::App` doesn't implement `Debug` [E0277]
-//~| ERROR `<<T as Case1>::C as Iterator>::Item` is not an iterator [E0277]
-//~| ERROR `<<T as Case1>::C as Iterator>::Item` cannot be sent between threads safely [E0277]
-//~| ERROR `<<T as Case1>::C as Iterator>::Item` cannot be shared between threads safely [E0277]
     fn assert_a<_0, A>() where A: Iterator<Item = _0>, _0: Debug {}
     assert_a::<_, T::A>();
 
diff --git a/src/test/ui/associated-type-bounds/bad-bounds-on-assoc-in-trait.stderr b/src/test/ui/associated-type-bounds/bad-bounds-on-assoc-in-trait.stderr
index 49b5e7fbb89..20a087a85a6 100644
--- a/src/test/ui/associated-type-bounds/bad-bounds-on-assoc-in-trait.stderr
+++ b/src/test/ui/associated-type-bounds/bad-bounds-on-assoc-in-trait.stderr
@@ -1,79 +1,54 @@
-error[E0277]: `<L1 as Lam<&'a u8>>::App` doesn't implement `Debug`
-  --> $DIR/bad-bounds-on-assoc-in-trait.rs:29:6
-   |
-LL | trait Case1 {
-   |       ----- required by a bound in this
-...
-LL |                 Debug
-   |                 ----- required by this bound in `Case1`
-...
-LL | impl Case1 for S1 {
-   |      ^^^^^ `<L1 as Lam<&'a u8>>::App` cannot be formatted using `{:?}` because it doesn't implement `Debug`
-   |
-   = help: the trait `for<'a> Debug` is not implemented for `<L1 as Lam<&'a u8>>::App`
-
-error[E0277]: `<<T as Case1>::C as Iterator>::Item` is not an iterator
-  --> $DIR/bad-bounds-on-assoc-in-trait.rs:34:20
-   |
-LL | fn assume_case1<T: Case1>() {
-   |                    ^^^^^ `<<T as Case1>::C as Iterator>::Item` is not an iterator
-   |
-   = help: the trait `Iterator` is not implemented for `<<T as Case1>::C as Iterator>::Item`
+error[E0277]: `<<Self as Case1>::C as std::iter::Iterator>::Item` is not an iterator
+  --> $DIR/bad-bounds-on-assoc-in-trait.rs:22:5
+   |
+LL | /     type C: Clone + Iterator<Item:
+LL | |         Send + Iterator<Item:
+LL | |             for<'a> Lam<&'a u8, App:
+LL | |                 Debug
+LL | |             >
+LL | |         > + Sync>;
+   | |__________________^ `<<Self as Case1>::C as std::iter::Iterator>::Item` is not an iterator
+   |
+   = help: the trait `std::iter::Iterator` is not implemented for `<<Self as Case1>::C as std::iter::Iterator>::Item`
 help: consider further restricting the associated type
    |
-LL | fn assume_case1<T: Case1>() where <<T as Case1>::C as Iterator>::Item: Iterator {
-   |                             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+LL | trait Case1 where <<Self as Case1>::C as std::iter::Iterator>::Item: std::iter::Iterator {
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error[E0277]: `<<T as Case1>::C as Iterator>::Item` cannot be sent between threads safely
-  --> $DIR/bad-bounds-on-assoc-in-trait.rs:34:20
+error[E0277]: `<<Self as Case1>::C as std::iter::Iterator>::Item` cannot be sent between threads safely
+  --> $DIR/bad-bounds-on-assoc-in-trait.rs:23:9
    |
-LL | trait Case1 {
-   |       ----- required by a bound in this
-LL |     type C: Clone + Iterator<Item:
 LL |         Send + Iterator<Item:
-   |         ---- required by this bound in `Case1`
-...
-LL | fn assume_case1<T: Case1>() {
-   |                    ^^^^^ `<<T as Case1>::C as Iterator>::Item` cannot be sent between threads safely
+   |         ^^^^ `<<Self as Case1>::C as std::iter::Iterator>::Item` cannot be sent between threads safely
    |
-   = help: the trait `Send` is not implemented for `<<T as Case1>::C as Iterator>::Item`
+  ::: $SRC_DIR/libcore/marker.rs:LL:COL
+   |
+LL | pub unsafe auto trait Send {
+   | -------------------------- required by this bound in `std::marker::Send`
+   |
+   = help: the trait `std::marker::Send` is not implemented for `<<Self as Case1>::C as std::iter::Iterator>::Item`
 help: consider further restricting the associated type
    |
-LL | fn assume_case1<T: Case1>() where <<T as Case1>::C as Iterator>::Item: Send {
-   |                             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+LL | trait Case1 where <<Self as Case1>::C as std::iter::Iterator>::Item: std::marker::Send {
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error[E0277]: `<<T as Case1>::C as Iterator>::Item` cannot be shared between threads safely
-  --> $DIR/bad-bounds-on-assoc-in-trait.rs:34:20
+error[E0277]: `<<Self as Case1>::C as std::iter::Iterator>::Item` cannot be shared between threads safely
+  --> $DIR/bad-bounds-on-assoc-in-trait.rs:27:13
    |
-LL | trait Case1 {
-   |       ----- required by a bound in this
-...
 LL |         > + Sync>;
-   |             ---- required by this bound in `Case1`
-...
-LL | fn assume_case1<T: Case1>() {
-   |                    ^^^^^ `<<T as Case1>::C as Iterator>::Item` cannot be shared between threads safely
+   |             ^^^^ `<<Self as Case1>::C as std::iter::Iterator>::Item` cannot be shared between threads safely
    |
-   = help: the trait `Sync` is not implemented for `<<T as Case1>::C as Iterator>::Item`
-help: consider further restricting the associated type
+  ::: $SRC_DIR/libcore/marker.rs:LL:COL
    |
-LL | fn assume_case1<T: Case1>() where <<T as Case1>::C as Iterator>::Item: Sync {
-   |                             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
-error[E0277]: `<_ as Lam<&'a u8>>::App` doesn't implement `Debug`
-  --> $DIR/bad-bounds-on-assoc-in-trait.rs:34:20
+LL | pub unsafe auto trait Sync {
+   | -------------------------- required by this bound in `std::marker::Sync`
    |
-LL | trait Case1 {
-   |       ----- required by a bound in this
-...
-LL |                 Debug
-   |                 ----- required by this bound in `Case1`
-...
-LL | fn assume_case1<T: Case1>() {
-   |                    ^^^^^ `<_ as Lam<&'a u8>>::App` cannot be formatted using `{:?}` because it doesn't implement `Debug`
+   = help: the trait `std::marker::Sync` is not implemented for `<<Self as Case1>::C as std::iter::Iterator>::Item`
+help: consider further restricting the associated type
    |
-   = help: the trait `for<'a> Debug` is not implemented for `<_ as Lam<&'a u8>>::App`
+LL | trait Case1 where <<Self as Case1>::C as std::iter::Iterator>::Item: std::marker::Sync {
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: aborting due to 5 previous errors
+error: aborting due to 3 previous errors
 
 For more information about this error, try `rustc --explain E0277`.
diff --git a/src/test/ui/associated-type-bounds/bounds-on-assoc-in-trait.rs b/src/test/ui/associated-type-bounds/bounds-on-assoc-in-trait.rs
index ceca54b7cd7..4025e0fc5e1 100644
--- a/src/test/ui/associated-type-bounds/bounds-on-assoc-in-trait.rs
+++ b/src/test/ui/associated-type-bounds/bounds-on-assoc-in-trait.rs
@@ -1,4 +1,4 @@
-// check-pass
+// ignore-tidy-linelength
 
 #![feature(associated_type_bounds)]
 
@@ -18,6 +18,7 @@ impl<'a, 'b> Lam<&'a &'b u8> for L2 { type App = u8; }
 
 trait Case1 {
     type A: Iterator<Item: Debug>;
+    //~^ ERROR `<<Self as Case1>::A as std::iter::Iterator>::Item` doesn't implement `std::fmt::Debug`
 
     type B: Iterator<Item: 'static>;
 }
@@ -30,7 +31,11 @@ impl Case1 for S1 {
 
 // Ensure we don't have opaque `impl Trait` desugaring:
 
+// What is this supposed to mean? Rustc currently lowers `: Default` in the
+// bounds of `Out`, but trait selection can't find the bound since it applies
+// to a type other than `Self::Out`.
 pub trait Foo { type Out: Baz<Assoc: Default>; }
+//~^ ERROR trait bound `<<Self as Foo>::Out as Baz>::Assoc: std::default::Default` is not satisfied
 pub trait Baz { type Assoc; }
 
 #[derive(Default)]
diff --git a/src/test/ui/associated-type-bounds/bounds-on-assoc-in-trait.stderr b/src/test/ui/associated-type-bounds/bounds-on-assoc-in-trait.stderr
new file mode 100644
index 00000000000..2be37285e29
--- /dev/null
+++ b/src/test/ui/associated-type-bounds/bounds-on-assoc-in-trait.stderr
@@ -0,0 +1,36 @@
+error[E0277]: `<<Self as Case1>::A as std::iter::Iterator>::Item` doesn't implement `std::fmt::Debug`
+  --> $DIR/bounds-on-assoc-in-trait.rs:20:28
+   |
+LL |     type A: Iterator<Item: Debug>;
+   |                            ^^^^^ `<<Self as Case1>::A as std::iter::Iterator>::Item` cannot be formatted using `{:?}` because it doesn't implement `std::fmt::Debug`
+   | 
+  ::: $SRC_DIR/libcore/fmt/mod.rs:LL:COL
+   |
+LL | pub trait Debug {
+   | --------------- required by this bound in `std::fmt::Debug`
+   |
+   = help: the trait `std::fmt::Debug` is not implemented for `<<Self as Case1>::A as std::iter::Iterator>::Item`
+help: consider further restricting the associated type
+   |
+LL | trait Case1 where <<Self as Case1>::A as std::iter::Iterator>::Item: std::fmt::Debug {
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error[E0277]: the trait bound `<<Self as Foo>::Out as Baz>::Assoc: std::default::Default` is not satisfied
+  --> $DIR/bounds-on-assoc-in-trait.rs:37:38
+   |
+LL | pub trait Foo { type Out: Baz<Assoc: Default>; }
+   |                                      ^^^^^^^ the trait `std::default::Default` is not implemented for `<<Self as Foo>::Out as Baz>::Assoc`
+   | 
+  ::: $SRC_DIR/libcore/default.rs:LL:COL
+   |
+LL | pub trait Default: Sized {
+   | ------------------------ required by this bound in `std::default::Default`
+   |
+help: consider further restricting the associated type
+   |
+LL | pub trait Foo where <<Self as Foo>::Out as Baz>::Assoc: std::default::Default { type Out: Baz<Assoc: Default>; }
+   |               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0277`.
diff --git a/src/test/ui/associated-type-bounds/duplicate.stderr b/src/test/ui/associated-type-bounds/duplicate.stderr
index 77cd88e524f..b5941fb80c7 100644
--- a/src/test/ui/associated-type-bounds/duplicate.stderr
+++ b/src/test/ui/associated-type-bounds/duplicate.stderr
@@ -512,31 +512,7 @@ LL | trait TRSW3 where Self: Iterator<Item: 'static, Item: 'static> {}
    |                                  `Item` bound here first
 
 error[E0719]: the value of the associated type `Item` (from trait `Iterator`) is already specified
-  --> $DIR/duplicate.rs:145:43
-   |
-LL | trait TRA1 { type A: Iterator<Item: Copy, Item: Send>; }
-   |                               ----------  ^^^^^^^^^^ re-bound here
-   |                               |
-   |                               `Item` bound here first
-
-error[E0719]: the value of the associated type `Item` (from trait `Iterator`) is already specified
-  --> $DIR/duplicate.rs:147:43
-   |
-LL | trait TRA2 { type A: Iterator<Item: Copy, Item: Copy>; }
-   |                               ----------  ^^^^^^^^^^ re-bound here
-   |                               |
-   |                               `Item` bound here first
-
-error[E0719]: the value of the associated type `Item` (from trait `Iterator`) is already specified
-  --> $DIR/duplicate.rs:149:46
-   |
-LL | trait TRA3 { type A: Iterator<Item: 'static, Item: 'static>; }
-   |                               -------------  ^^^^^^^^^^^^^ re-bound here
-   |                               |
-   |                               `Item` bound here first
-
-error[E0719]: the value of the associated type `Item` (from trait `Iterator`) is already specified
-  --> $DIR/duplicate.rs:152:40
+  --> $DIR/duplicate.rs:167:40
    |
 LL | type TADyn1 = dyn Iterator<Item: Copy, Item: Send>;
    |                            ----------  ^^^^^^^^^^ re-bound here
diff --git a/src/test/ui/associated-types/associated-types-unconstrained.stderr b/src/test/ui/associated-types/associated-types-unconstrained.stderr
index 2914a7f868b..9d084203e3a 100644
--- a/src/test/ui/associated-types/associated-types-unconstrained.stderr
+++ b/src/test/ui/associated-types/associated-types-unconstrained.stderr
@@ -1,11 +1,14 @@
-error[E0284]: type annotations needed
+error[E0283]: type annotations needed
   --> $DIR/associated-types-unconstrained.rs:14:20
    |
+LL |     fn bar() -> isize;
+   |     ------------------ required by `Foo::bar`
+...
 LL |     let x: isize = Foo::bar();
    |                    ^^^^^^^^ cannot infer type
    |
-   = note: cannot satisfy `<_ as Foo>::A == _`
+   = note: cannot satisfy `_: Foo`
 
 error: aborting due to previous error
 
-For more information about this error, try `rustc --explain E0284`.
+For more information about this error, try `rustc --explain E0283`.
diff --git a/src/test/ui/associated-types/defaults-cyclic-fail-1.rs b/src/test/ui/associated-types/defaults-cyclic-fail-1.rs
index fa75f6bc152..afb2b3df716 100644
--- a/src/test/ui/associated-types/defaults-cyclic-fail-1.rs
+++ b/src/test/ui/associated-types/defaults-cyclic-fail-1.rs
@@ -6,11 +6,8 @@ trait Tr {
     type B = Self::A;
 }
 
-// ...but is an error in any impl that doesn't override at least one of the defaults
 impl Tr for () {}
-//~^ ERROR overflow evaluating the requirement
 
-// As soon as at least one is redefined, it works:
 impl Tr for u8 {
     type A = u8;
 }
@@ -24,16 +21,14 @@ impl Tr for u32 {
     type B = u8;
 }
 
-// ...but only if this actually breaks the cycle
+// ...but not in an impl that redefines one of the types.
 impl Tr for bool {
-    //~^ ERROR type mismatch resolving `<bool as Tr>::B == _`
     type A = Box<Self::B>;
     //~^ ERROR type mismatch resolving `<bool as Tr>::B == _`
 }
 // (the error is shown twice for some reason)
 
 impl Tr for usize {
-    //~^ ERROR type mismatch resolving `<usize as Tr>::B == _`
     type B = &'static Self::A;
     //~^ ERROR type mismatch resolving `<usize as Tr>::A == _`
 }
diff --git a/src/test/ui/associated-types/defaults-cyclic-fail-1.stderr b/src/test/ui/associated-types/defaults-cyclic-fail-1.stderr
index 0aea30b1112..28decb0934c 100644
--- a/src/test/ui/associated-types/defaults-cyclic-fail-1.stderr
+++ b/src/test/ui/associated-types/defaults-cyclic-fail-1.stderr
@@ -1,34 +1,16 @@
-error[E0275]: overflow evaluating the requirement `<() as Tr>::B == _`
-  --> $DIR/defaults-cyclic-fail-1.rs:10:6
-   |
-LL | impl Tr for () {}
-   |      ^^
-
-error[E0271]: type mismatch resolving `<bool as Tr>::B == _`
-  --> $DIR/defaults-cyclic-fail-1.rs:28:6
-   |
-LL | impl Tr for bool {
-   |      ^^ cyclic type of infinite size
-
-error[E0271]: type mismatch resolving `<usize as Tr>::B == _`
-  --> $DIR/defaults-cyclic-fail-1.rs:35:6
-   |
-LL | impl Tr for usize {
-   |      ^^ cyclic type of infinite size
-
-error[E0271]: type mismatch resolving `<bool as Tr>::B == _`
-  --> $DIR/defaults-cyclic-fail-1.rs:30:5
+error[E0275]: overflow evaluating the requirement `<bool as Tr>::B`
+  --> $DIR/defaults-cyclic-fail-1.rs:26:5
    |
 LL |     type A = Box<Self::B>;
    |     ^^^^^^^^^^^^^^^^^^^^^^ cyclic type of infinite size
 
-error[E0271]: type mismatch resolving `<usize as Tr>::A == _`
-  --> $DIR/defaults-cyclic-fail-1.rs:37:5
+error[E0275]: overflow evaluating the requirement `<usize as Tr>::A`
+  --> $DIR/defaults-cyclic-fail-1.rs:32:5
    |
 LL |     type B = &'static Self::A;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^ cyclic type of infinite size
 
-error: aborting due to 5 previous errors
+error: aborting due to 2 previous errors
 
 Some errors have detailed explanations: E0271, E0275.
 For more information about an error, try `rustc --explain E0271`.
diff --git a/src/test/ui/associated-types/defaults-cyclic-fail-2.rs b/src/test/ui/associated-types/defaults-cyclic-fail-2.rs
index edcd310908a..ba4bb0d5a29 100644
--- a/src/test/ui/associated-types/defaults-cyclic-fail-2.rs
+++ b/src/test/ui/associated-types/defaults-cyclic-fail-2.rs
@@ -8,11 +8,8 @@ trait Tr {
     type B = Box<Self::A>;
 }
 
-// ...but is an error in any impl that doesn't override at least one of the defaults
 impl Tr for () {}
-//~^ ERROR type mismatch resolving `<() as Tr>::B == _`
 
-// As soon as at least one is redefined, it works:
 impl Tr for u8 {
     type A = u8;
 }
@@ -26,16 +23,13 @@ impl Tr for u32 {
     type B = u8;
 }
 
-// ...but only if this actually breaks the cycle
 impl Tr for bool {
-    //~^ ERROR type mismatch resolving `<bool as Tr>::B == _`
     type A = Box<Self::B>;
     //~^ ERROR type mismatch resolving `<bool as Tr>::B == _`
 }
 // (the error is shown twice for some reason)
 
 impl Tr for usize {
-    //~^ ERROR type mismatch resolving `<usize as Tr>::B == _`
     type B = &'static Self::A;
     //~^ ERROR type mismatch resolving `<usize as Tr>::A == _`
 }
diff --git a/src/test/ui/associated-types/defaults-cyclic-fail-2.stderr b/src/test/ui/associated-types/defaults-cyclic-fail-2.stderr
index f39021c30ed..6b6d5348c15 100644
--- a/src/test/ui/associated-types/defaults-cyclic-fail-2.stderr
+++ b/src/test/ui/associated-types/defaults-cyclic-fail-2.stderr
@@ -1,33 +1,15 @@
-error[E0271]: type mismatch resolving `<() as Tr>::B == _`
-  --> $DIR/defaults-cyclic-fail-2.rs:12:6
-   |
-LL | impl Tr for () {}
-   |      ^^ cyclic type of infinite size
-
-error[E0271]: type mismatch resolving `<bool as Tr>::B == _`
-  --> $DIR/defaults-cyclic-fail-2.rs:30:6
-   |
-LL | impl Tr for bool {
-   |      ^^ cyclic type of infinite size
-
-error[E0271]: type mismatch resolving `<usize as Tr>::B == _`
-  --> $DIR/defaults-cyclic-fail-2.rs:37:6
-   |
-LL | impl Tr for usize {
-   |      ^^ cyclic type of infinite size
-
-error[E0271]: type mismatch resolving `<bool as Tr>::B == _`
-  --> $DIR/defaults-cyclic-fail-2.rs:32:5
+error[E0275]: overflow evaluating the requirement `<bool as Tr>::B`
+  --> $DIR/defaults-cyclic-fail-2.rs:27:5
    |
 LL |     type A = Box<Self::B>;
    |     ^^^^^^^^^^^^^^^^^^^^^^ cyclic type of infinite size
 
-error[E0271]: type mismatch resolving `<usize as Tr>::A == _`
-  --> $DIR/defaults-cyclic-fail-2.rs:39:5
+error[E0275]: overflow evaluating the requirement `<usize as Tr>::A`
+  --> $DIR/defaults-cyclic-fail-2.rs:33:5
    |
 LL |     type B = &'static Self::A;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^ cyclic type of infinite size
 
-error: aborting due to 5 previous errors
+error: aborting due to 2 previous errors
 
 For more information about this error, try `rustc --explain E0271`.
diff --git a/src/test/ui/associated-types/defaults-suitability.rs b/src/test/ui/associated-types/defaults-suitability.rs
index 30c2555df8b..69be300b16f 100644
--- a/src/test/ui/associated-types/defaults-suitability.rs
+++ b/src/test/ui/associated-types/defaults-suitability.rs
@@ -1,10 +1,8 @@
 //! Checks that associated type defaults are properly validated.
 //!
 //! This means:
-//! * Default types are wfchecked
 //! * Default types are checked against where clauses on the assoc. type
-//!   (eg. `type Assoc: Clone = NotClone`), and also against where clauses on
-//!   the trait itself when possible
+//!   (eg. `type Assoc: Clone = NotClone`)
 
 #![feature(associated_type_defaults)]
 
@@ -17,15 +15,12 @@ trait Tr {
 }
 
 // Where-clauses defined on the trait must also be considered
-trait Tr2 where Self::Ty: Clone {
-    //~^ ERROR the trait bound `NotClone: Clone` is not satisfied
+trait Tr2
+where
+    Self::Ty: Clone,
+{
     type Ty = NotClone;
-}
-
-// Independent of where-clauses (there are none here), default types must always be wf
-trait Tr3 {
-    type Ty = Vec<[u8]>;
-    //~^ ERROR the size for values of type `[u8]` cannot be known at compilation time
+    //~^ ERROR the trait bound `NotClone: std::clone::Clone` is not satisfied
 }
 
 // Involved type parameters must fulfill all bounds required by defaults that mention them
@@ -43,25 +38,24 @@ trait Bar: Sized {
 trait IsU8<T> {}
 impl<T> IsU8<u8> for T {}
 
-// Test that mentioning the assoc. type inside where clauses works
+// Test that mentioning the assoc. type inside where clauses is not allowed
 trait C where
     Vec<Self::Assoc>: Clone,
     Self::Assoc: IsU8<Self::Assoc>,
     bool: IsU8<Self::Assoc>,
 {
     type Assoc = u8;
+    //~^ ERROR the trait bound `u8: IsU8<<Self as C>::Assoc>` is not satisfied
 }
 
 // Test that we get all expected errors if that default is unsuitable
 trait D where
     Vec<Self::Assoc>: Clone,
-    //~^ ERROR the trait bound `NotClone: Clone` is not satisfied
     Self::Assoc: IsU8<Self::Assoc>,
-    //~^ ERROR the trait bound `NotClone: IsU8<NotClone>` is not satisfied
     bool: IsU8<Self::Assoc>,
-    //~^ ERROR the trait bound `bool: IsU8<NotClone>` is not satisfied
 {
     type Assoc = NotClone;
+    //~^ ERROR the trait bound `NotClone: IsU8<<Self as D>::Assoc>` is not satisfied
 }
 
 // Test behavior of the check when defaults refer to other defaults:
@@ -85,18 +79,20 @@ trait Foo25<T: Clone> {
 
 // Adding the `Baz: Clone` bound isn't enough since the default is type
 // parameter `T`, which also might not be `Clone`.
-trait Foo3<T> where
+trait Foo3<T>
+where
     Self::Bar: Clone,
     Self::Baz: Clone,
-    //~^ ERROR the trait bound `T: Clone` is not satisfied
 {
     type Bar = Vec<Self::Baz>;
     type Baz = T;
+    //~^ ERROR the trait bound `T: std::clone::Clone` is not satisfied
 }
 
 // This one finally works, with `Clone` bounds on all assoc. types and the type
 // parameter.
-trait Foo4<T> where
+trait Foo4<T>
+where
     T: Clone,
 {
     type Bar: Clone = Vec<Self::Baz>;
diff --git a/src/test/ui/associated-types/defaults-suitability.stderr b/src/test/ui/associated-types/defaults-suitability.stderr
index c2ad4c5824e..4d8e6f1584d 100644
--- a/src/test/ui/associated-types/defaults-suitability.stderr
+++ b/src/test/ui/associated-types/defaults-suitability.stderr
@@ -1,27 +1,31 @@
-error[E0277]: the trait bound `NotClone: Clone` is not satisfied
-  --> $DIR/defaults-suitability.rs:15:14
+error[E0277]: the trait bound `NotClone: std::clone::Clone` is not satisfied
+  --> $DIR/defaults-suitability.rs:13:5
    |
-LL | trait Tr {
-   | -------- required by `Tr`
 LL |     type Ty: Clone = NotClone;
-   |              ^^^^^ the trait `Clone` is not implemented for `NotClone`
+   |     ^^^^^^^^^-----^^^^^^^^^^^^
+   |     |        |
+   |     |        required by this bound in `Tr::Ty`
+   |     the trait `std::clone::Clone` is not implemented for `NotClone`
 
-error[E0277]: the trait bound `NotClone: Clone` is not satisfied
-  --> $DIR/defaults-suitability.rs:20:27
+error[E0277]: the trait bound `NotClone: std::clone::Clone` is not satisfied
+  --> $DIR/defaults-suitability.rs:19:5
    |
 LL | trait Tr2 where Self::Ty: Clone {
-   | --------------------------^^^^^
-   | |                         |
-   | |                         the trait `Clone` is not implemented for `NotClone`
-   | required by `Tr2`
+   |                           ----- required by this bound in `Tr2::Ty`
+LL |     type Ty = NotClone;
+   |     ^^^^^--^^^^^^^^^^^^
+   |     |    |
+   |     |    required by a bound in this
+   |     the trait `std::clone::Clone` is not implemented for `NotClone`
 
-error[E0277]: the trait bound `T: Clone` is not satisfied
-  --> $DIR/defaults-suitability.rs:33:15
+error[E0277]: the trait bound `T: std::clone::Clone` is not satisfied
+  --> $DIR/defaults-suitability.rs:25:5
    |
-LL | trait Foo<T> {
-   | ------------ required by `Foo`
 LL |     type Bar: Clone = Vec<T>;
-   |               ^^^^^ the trait `Clone` is not implemented for `T`
+   |     ^^^^^^^^^^-----^^^^^^^^^^
+   |     |         |
+   |     |         required by this bound in `Foo::Bar`
+   |     the trait `std::clone::Clone` is not implemented for `T`
    |
    = note: required because of the requirements on the impl of `Clone` for `Vec<T>`
 help: consider restricting type parameter `T`
@@ -30,64 +34,46 @@ LL | trait Foo<T: Clone> {
    |            ^^^^^^^
 
 error[E0277]: the trait bound `(): Foo<Self>` is not satisfied
-  --> $DIR/defaults-suitability.rs:39:17
+  --> $DIR/defaults-suitability.rs:31:5
    |
-LL | trait Bar: Sized {
-   | ---------------- required by `Bar`
-LL |     // `(): Foo<Self>` might hold for some possible impls but not all.
 LL |     type Assoc: Foo<Self> = ();
-   |                 ^^^^^^^^^ the trait `Foo<Self>` is not implemented for `()`
+   |     ^^^^^^^^^^^^---------^^^^^^
+   |     |           |
+   |     |           required by this bound in `Bar::Assoc`
+   |     the trait `Foo<Self>` is not implemented for `()`
 
-error[E0277]: the trait bound `NotClone: IsU8<NotClone>` is not satisfied
-  --> $DIR/defaults-suitability.rs:59:18
-   |
-LL | / trait D where
-LL | |     Vec<Self::Assoc>: Clone,
-LL | |
-LL | |     Self::Assoc: IsU8<Self::Assoc>,
-   | |                  ^^^^^^^^^^^^^^^^^ the trait `IsU8<NotClone>` is not implemented for `NotClone`
-...  |
-LL | |     type Assoc = NotClone;
-LL | | }
-   | |_- required by `D`
+error[E0277]: the trait bound `u8: IsU8<<Self as C>::Assoc>` is not satisfied
+  --> $DIR/defaults-suitability.rs:44:5
+   |
+LL |     Self::Assoc: IsU8<Self::Assoc>,
+   |                  ----------------- required by this bound in `C::Assoc`
+...
+LL |     type Assoc = u8;
+   |     ^^^^^-----^^^^^^
+   |     |    |
+   |     |    required by a bound in this
+   |     the trait `IsU8<<Self as C>::Assoc>` is not implemented for `u8`
 
-error[E0277]: the trait bound `bool: IsU8<NotClone>` is not satisfied
-  --> $DIR/defaults-suitability.rs:61:11
-   |
-LL | / trait D where
-LL | |     Vec<Self::Assoc>: Clone,
-LL | |
-LL | |     Self::Assoc: IsU8<Self::Assoc>,
-LL | |
-LL | |     bool: IsU8<Self::Assoc>,
-   | |           ^^^^^^^^^^^^^^^^^ the trait `IsU8<NotClone>` is not implemented for `bool`
-...  |
-LL | |     type Assoc = NotClone;
-LL | | }
-   | |_- required by `D`
+error[E0277]: the trait bound `NotClone: IsU8<<Self as D>::Assoc>` is not satisfied
+  --> $DIR/defaults-suitability.rs:54:5
+   |
+LL |     Self::Assoc: IsU8<Self::Assoc>,
+   |                  ----------------- required by this bound in `D::Assoc`
+...
+LL |     type Assoc = NotClone;
+   |     ^^^^^-----^^^^^^^^^^^^
+   |     |    |
+   |     |    required by a bound in this
+   |     the trait `IsU8<<Self as D>::Assoc>` is not implemented for `NotClone`
 
-error[E0277]: the trait bound `NotClone: Clone` is not satisfied
-  --> $DIR/defaults-suitability.rs:57:23
-   |
-LL | / trait D where
-LL | |     Vec<Self::Assoc>: Clone,
-   | |                       ^^^^^ the trait `Clone` is not implemented for `NotClone`
-LL | |
-LL | |     Self::Assoc: IsU8<Self::Assoc>,
-...  |
-LL | |     type Assoc = NotClone;
-LL | | }
-   | |_- required by `D`
-   |
-   = note: required because of the requirements on the impl of `Clone` for `Vec<NotClone>`
-
-error[E0277]: the trait bound `<Self as Foo2<T>>::Baz: Clone` is not satisfied
-  --> $DIR/defaults-suitability.rs:72:15
+error[E0277]: the trait bound `<Self as Foo2<T>>::Baz: std::clone::Clone` is not satisfied
+  --> $DIR/defaults-suitability.rs:63:5
    |
-LL | trait Foo2<T> {
-   | ------------- required by `Foo2`
 LL |     type Bar: Clone = Vec<Self::Baz>;
-   |               ^^^^^ the trait `Clone` is not implemented for `<Self as Foo2<T>>::Baz`
+   |     ^^^^^^^^^^-----^^^^^^^^^^^^^^^^^^
+   |     |         |
+   |     |         required by this bound in `Foo2::Bar`
+   |     the trait `std::clone::Clone` is not implemented for `<Self as Foo2<T>>::Baz`
    |
    = note: required because of the requirements on the impl of `Clone` for `Vec<<Self as Foo2<T>>::Baz>`
 help: consider further restricting the associated type
@@ -95,13 +81,14 @@ help: consider further restricting the associated type
 LL | trait Foo2<T> where <Self as Foo2<T>>::Baz: Clone {
    |               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error[E0277]: the trait bound `<Self as Foo25<T>>::Baz: Clone` is not satisfied
-  --> $DIR/defaults-suitability.rs:81:15
+error[E0277]: the trait bound `<Self as Foo25<T>>::Baz: std::clone::Clone` is not satisfied
+  --> $DIR/defaults-suitability.rs:72:5
    |
-LL | trait Foo25<T: Clone> {
-   | --------------------- required by `Foo25`
 LL |     type Bar: Clone = Vec<Self::Baz>;
-   |               ^^^^^ the trait `Clone` is not implemented for `<Self as Foo25<T>>::Baz`
+   |     ^^^^^^^^^^-----^^^^^^^^^^^^^^^^^^
+   |     |         |
+   |     |         required by this bound in `Foo25::Bar`
+   |     the trait `std::clone::Clone` is not implemented for `<Self as Foo25<T>>::Baz`
    |
    = note: required because of the requirements on the impl of `Clone` for `Vec<<Self as Foo25<T>>::Baz>`
 help: consider further restricting the associated type
@@ -109,37 +96,23 @@ help: consider further restricting the associated type
 LL | trait Foo25<T: Clone> where <Self as Foo25<T>>::Baz: Clone {
    |                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error[E0277]: the trait bound `T: Clone` is not satisfied
-  --> $DIR/defaults-suitability.rs:90:16
-   |
-LL | / trait Foo3<T> where
-LL | |     Self::Bar: Clone,
-LL | |     Self::Baz: Clone,
-   | |                ^^^^^ the trait `Clone` is not implemented for `T`
-LL | |
-...  |
-LL | |     type Baz = T;
-LL | | }
-   | |_- required by `Foo3`
+error[E0277]: the trait bound `T: std::clone::Clone` is not satisfied
+  --> $DIR/defaults-suitability.rs:84:5
+   |
+LL |     Self::Baz: Clone,
+   |                ----- required by this bound in `Foo3::Baz`
+...
+LL |     type Baz = T;
+   |     ^^^^^---^^^^^
+   |     |    |
+   |     |    required by a bound in this
+   |     the trait `std::clone::Clone` is not implemented for `T`
    |
 help: consider further restricting type parameter `T`
    |
 LL |     Self::Baz: Clone, T: Clone
    |                     ^^^^^^^^^^
 
-error[E0277]: the size for values of type `[u8]` cannot be known at compilation time
-  --> $DIR/defaults-suitability.rs:27:5
-   |
-LL |     type Ty = Vec<[u8]>;
-   |     ^^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
-   | 
-  ::: $SRC_DIR/alloc/src/vec.rs:LL:COL
-   |
-LL | pub struct Vec<T> {
-   |                - required by this bound in `Vec`
-   |
-   = help: the trait `Sized` is not implemented for `[u8]`
-
-error: aborting due to 11 previous errors
+error: aborting due to 9 previous errors
 
 For more information about this error, try `rustc --explain E0277`.
diff --git a/src/test/ui/associated-types/defaults-unsound-62211-1.rs b/src/test/ui/associated-types/defaults-unsound-62211-1.rs
index f283d22b3c7..093e32f66be 100644
--- a/src/test/ui/associated-types/defaults-unsound-62211-1.rs
+++ b/src/test/ui/associated-types/defaults-unsound-62211-1.rs
@@ -11,22 +11,13 @@
 
 use std::{
     fmt::Display,
-    ops::{AddAssign, Deref}
+    ops::{AddAssign, Deref},
 };
 
-
 trait UncheckedCopy: Sized {
     // This Output is said to be Copy. Yet we default to Self
     // and it's accepted, not knowing if Self ineed is Copy
-    type Output: Copy
-    //~^ ERROR the trait bound `Self: Copy` is not satisfied
-    + Deref<Target = str>
-    //~^ ERROR the trait bound `Self: Deref` is not satisfied
-    + AddAssign<&'static str>
-    //~^ ERROR cannot add-assign `&'static str` to `Self`
-    + From<Self>
-    + Display = Self;
-    //~^ ERROR `Self` doesn't implement `std::fmt::Display`
+    type Output: Copy + Deref<Target = str> + AddAssign<&'static str> + From<Self> + Display = Self;
 
     // We said the Output type was Copy, so we can Copy it freely!
     fn unchecked_copy(other: &Self::Output) -> Self::Output {
@@ -39,10 +30,6 @@ trait UncheckedCopy: Sized {
 }
 
 impl<T> UncheckedCopy for T {}
-//~^ ERROR `T` doesn't implement `std::fmt::Display`
-//~| ERROR the trait bound `T: Deref` is not satisfied
-//~| ERROR cannot add-assign `&'static str` to `T`
-//~| ERROR the trait bound `T: Copy` is not satisfied
 
 fn bug<T: UncheckedCopy>(origin: T) {
     let origin = T::make_origin(origin);
diff --git a/src/test/ui/associated-types/defaults-unsound-62211-1.stderr b/src/test/ui/associated-types/defaults-unsound-62211-1.stderr
index 29a7c2eab41..a8584d6dc5c 100644
--- a/src/test/ui/associated-types/defaults-unsound-62211-1.stderr
+++ b/src/test/ui/associated-types/defaults-unsound-62211-1.stderr
@@ -1,53 +1,19 @@
-error[E0277]: the trait bound `Self: Copy` is not satisfied
-  --> $DIR/defaults-unsound-62211-1.rs:21:18
-   |
-LL | trait UncheckedCopy: Sized {
-   | -------------------------- required by `UncheckedCopy`
-...
-LL |     type Output: Copy
-   |                  ^^^^ the trait `Copy` is not implemented for `Self`
-   |
-help: consider further restricting `Self`
-   |
-LL | trait UncheckedCopy: Sized + Copy {
-   |                            ^^^^^^
-
-error[E0277]: cannot add-assign `&'static str` to `Self`
-  --> $DIR/defaults-unsound-62211-1.rs:25:7
-   |
-LL | trait UncheckedCopy: Sized {
-   | -------------------------- required by `UncheckedCopy`
-...
-LL |     + AddAssign<&'static str>
-   |       ^^^^^^^^^^^^^^^^^^^^^^^ no implementation for `Self += &'static str`
-   |
-help: consider further restricting `Self`
-   |
-LL | trait UncheckedCopy: Sized + AddAssign<&'static str> {
-   |                            ^^^^^^^^^^^^^^^^^^^^^^^^^
-
-error[E0277]: the trait bound `Self: Deref` is not satisfied
-  --> $DIR/defaults-unsound-62211-1.rs:23:7
-   |
-LL | trait UncheckedCopy: Sized {
-   | -------------------------- required by `UncheckedCopy`
-...
-LL |     + Deref<Target = str>
-   |       ^^^^^^^^^^^^^^^^^^^ the trait `Deref` is not implemented for `Self`
-   |
-help: consider further restricting `Self`
-   |
-LL | trait UncheckedCopy: Sized + Deref {
-   |                            ^^^^^^^
-
 error[E0277]: `Self` doesn't implement `std::fmt::Display`
-  --> $DIR/defaults-unsound-62211-1.rs:28:7
-   |
-LL | trait UncheckedCopy: Sized {
-   | -------------------------- required by `UncheckedCopy`
-...
-LL |     + Display = Self;
-   |       ^^^^^^^ `Self` cannot be formatted with the default formatter
+  --> $DIR/defaults-unsound-62211-1.rs:21:5
+   |
+LL |       type Output: Copy
+   |       ^    ------ required by a bound in this
+   |  _____|
+   | |
+LL | |
+LL | |
+LL | |
+...  |
+LL | |         + From<Self>
+LL | |         + Display = Self;
+   | |___________-------_______^ `Self` cannot be formatted with the default formatter
+   |             |
+   |             required by this bound in `UncheckedCopy::Output`
    |
    = note: in format strings you may be able to use `{:?}` (or {:#?} for pretty-print) instead
 help: consider further restricting `Self`
@@ -55,75 +21,71 @@ help: consider further restricting `Self`
 LL | trait UncheckedCopy: Sized + std::fmt::Display {
    |                            ^^^^^^^^^^^^^^^^^^^
 
-error[E0277]: `T` doesn't implement `std::fmt::Display`
-  --> $DIR/defaults-unsound-62211-1.rs:41:9
-   |
-LL | trait UncheckedCopy: Sized {
-   |       ------------- required by a bound in this
-...
-LL |     + Display = Self;
-   |       ------- required by this bound in `UncheckedCopy`
-...
-LL | impl<T> UncheckedCopy for T {}
-   |         ^^^^^^^^^^^^^ `T` cannot be formatted with the default formatter
-   |
-   = note: in format strings you may be able to use `{:?}` (or {:#?} for pretty-print) instead
-help: consider restricting type parameter `T`
+error[E0277]: the trait bound `Self: std::ops::Deref` is not satisfied
+  --> $DIR/defaults-unsound-62211-1.rs:21:5
+   |
+LL |       type Output: Copy
+   |       ^    ------ required by a bound in this
+   |  _____|
+   | |
+LL | |
+LL | |
+LL | |
+LL | |
+LL | |         + Deref<Target = str>
+   | |           ------------------- required by this bound in `UncheckedCopy::Output`
+LL | |         + AddAssign<&'static str>
+LL | |         + From<Self>
+LL | |         + Display = Self;
+   | |_________________________^ the trait `std::ops::Deref` is not implemented for `Self`
    |
-LL | impl<T: std::fmt::Display> UncheckedCopy for T {}
-   |       ^^^^^^^^^^^^^^^^^^^
-
-error[E0277]: the trait bound `T: Deref` is not satisfied
-  --> $DIR/defaults-unsound-62211-1.rs:41:9
-   |
-LL | trait UncheckedCopy: Sized {
-   |       ------------- required by a bound in this
-...
-LL |     + Deref<Target = str>
-   |       ------------------- required by this bound in `UncheckedCopy`
-...
-LL | impl<T> UncheckedCopy for T {}
-   |         ^^^^^^^^^^^^^ the trait `Deref` is not implemented for `T`
-   |
-help: consider restricting type parameter `T`
+help: consider further restricting `Self`
    |
-LL | impl<T: Deref> UncheckedCopy for T {}
-   |       ^^^^^^^
+LL | trait UncheckedCopy: Sized + Deref {
+   |                            ^^^^^^^
 
-error[E0277]: cannot add-assign `&'static str` to `T`
-  --> $DIR/defaults-unsound-62211-1.rs:41:9
-   |
-LL | trait UncheckedCopy: Sized {
-   |       ------------- required by a bound in this
-...
-LL |     + AddAssign<&'static str>
-   |       ----------------------- required by this bound in `UncheckedCopy`
-...
-LL | impl<T> UncheckedCopy for T {}
-   |         ^^^^^^^^^^^^^ no implementation for `T += &'static str`
+error[E0277]: cannot add-assign `&'static str` to `Self`
+  --> $DIR/defaults-unsound-62211-1.rs:21:5
+   |
+LL |       type Output: Copy
+   |       ^    ------ required by a bound in this
+   |  _____|
+   | |
+LL | |
+LL | |
+LL | |
+...  |
+LL | |         + AddAssign<&'static str>
+   | |           ----------------------- required by this bound in `UncheckedCopy::Output`
+LL | |         + From<Self>
+LL | |         + Display = Self;
+   | |_________________________^ no implementation for `Self += &'static str`
    |
-help: consider restricting type parameter `T`
+help: consider further restricting `Self`
    |
-LL | impl<T: AddAssign<&'static str>> UncheckedCopy for T {}
-   |       ^^^^^^^^^^^^^^^^^^^^^^^^^
+LL | trait UncheckedCopy: Sized + std::ops::AddAssign<&'static str> {
+   |                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error[E0277]: the trait bound `T: Copy` is not satisfied
-  --> $DIR/defaults-unsound-62211-1.rs:41:9
-   |
-LL | trait UncheckedCopy: Sized {
-   |       ------------- required by a bound in this
-...
-LL |     type Output: Copy
-   |                  ---- required by this bound in `UncheckedCopy`
-...
-LL | impl<T> UncheckedCopy for T {}
-   |         ^^^^^^^^^^^^^ the trait `Copy` is not implemented for `T`
+error[E0277]: the trait bound `Self: std::marker::Copy` is not satisfied
+  --> $DIR/defaults-unsound-62211-1.rs:21:5
+   |
+LL |       type Output: Copy
+   |       ^            ---- required by this bound in `UncheckedCopy::Output`
+   |  _____|
+   | |
+LL | |
+LL | |
+LL | |
+...  |
+LL | |         + From<Self>
+LL | |         + Display = Self;
+   | |_________________________^ the trait `std::marker::Copy` is not implemented for `Self`
    |
-help: consider restricting type parameter `T`
+help: consider further restricting `Self`
    |
-LL | impl<T: Copy> UncheckedCopy for T {}
-   |       ^^^^^^
+LL | trait UncheckedCopy: Sized + std::marker::Copy {
+   |                            ^^^^^^^^^^^^^^^^^^^
 
-error: aborting due to 8 previous errors
+error: aborting due to 4 previous errors
 
 For more information about this error, try `rustc --explain E0277`.
diff --git a/src/test/ui/associated-types/defaults-unsound-62211-2.rs b/src/test/ui/associated-types/defaults-unsound-62211-2.rs
index 5518cda3708..44bbdc9f52b 100644
--- a/src/test/ui/associated-types/defaults-unsound-62211-2.rs
+++ b/src/test/ui/associated-types/defaults-unsound-62211-2.rs
@@ -11,22 +11,13 @@
 
 use std::{
     fmt::Display,
-    ops::{AddAssign, Deref}
+    ops::{AddAssign, Deref},
 };
 
-
 trait UncheckedCopy: Sized {
     // This Output is said to be Copy. Yet we default to Self
     // and it's accepted, not knowing if Self ineed is Copy
-    type Output: Copy
-    //~^ ERROR the trait bound `Self: Copy` is not satisfied
-    + Deref<Target = str>
-    //~^ ERROR the trait bound `Self: Deref` is not satisfied
-    + AddAssign<&'static str>
-    //~^ ERROR cannot add-assign `&'static str` to `Self`
-    + From<Self>
-    + Display = Self;
-    //~^ ERROR `Self` doesn't implement `std::fmt::Display`
+    type Output: Copy + Deref<Target = str> + AddAssign<&'static str> + From<Self> + Display = Self;
 
     // We said the Output type was Copy, so we can Copy it freely!
     fn unchecked_copy(other: &Self::Output) -> Self::Output {
@@ -39,10 +30,6 @@ trait UncheckedCopy: Sized {
 }
 
 impl<T> UncheckedCopy for T {}
-//~^ ERROR `T` doesn't implement `std::fmt::Display`
-//~| ERROR the trait bound `T: Deref` is not satisfied
-//~| ERROR cannot add-assign `&'static str` to `T`
-//~| ERROR the trait bound `T: Copy` is not satisfied
 
 fn bug<T: UncheckedCopy>(origin: T) {
     let origin = T::make_origin(origin);
diff --git a/src/test/ui/associated-types/defaults-unsound-62211-2.stderr b/src/test/ui/associated-types/defaults-unsound-62211-2.stderr
index 49c66093bf0..6a8e3ff7b62 100644
--- a/src/test/ui/associated-types/defaults-unsound-62211-2.stderr
+++ b/src/test/ui/associated-types/defaults-unsound-62211-2.stderr
@@ -1,53 +1,19 @@
-error[E0277]: the trait bound `Self: Copy` is not satisfied
-  --> $DIR/defaults-unsound-62211-2.rs:21:18
-   |
-LL | trait UncheckedCopy: Sized {
-   | -------------------------- required by `UncheckedCopy`
-...
-LL |     type Output: Copy
-   |                  ^^^^ the trait `Copy` is not implemented for `Self`
-   |
-help: consider further restricting `Self`
-   |
-LL | trait UncheckedCopy: Sized + Copy {
-   |                            ^^^^^^
-
-error[E0277]: cannot add-assign `&'static str` to `Self`
-  --> $DIR/defaults-unsound-62211-2.rs:25:7
-   |
-LL | trait UncheckedCopy: Sized {
-   | -------------------------- required by `UncheckedCopy`
-...
-LL |     + AddAssign<&'static str>
-   |       ^^^^^^^^^^^^^^^^^^^^^^^ no implementation for `Self += &'static str`
-   |
-help: consider further restricting `Self`
-   |
-LL | trait UncheckedCopy: Sized + AddAssign<&'static str> {
-   |                            ^^^^^^^^^^^^^^^^^^^^^^^^^
-
-error[E0277]: the trait bound `Self: Deref` is not satisfied
-  --> $DIR/defaults-unsound-62211-2.rs:23:7
-   |
-LL | trait UncheckedCopy: Sized {
-   | -------------------------- required by `UncheckedCopy`
-...
-LL |     + Deref<Target = str>
-   |       ^^^^^^^^^^^^^^^^^^^ the trait `Deref` is not implemented for `Self`
-   |
-help: consider further restricting `Self`
-   |
-LL | trait UncheckedCopy: Sized + Deref {
-   |                            ^^^^^^^
-
 error[E0277]: `Self` doesn't implement `std::fmt::Display`
-  --> $DIR/defaults-unsound-62211-2.rs:28:7
-   |
-LL | trait UncheckedCopy: Sized {
-   | -------------------------- required by `UncheckedCopy`
-...
-LL |     + Display = Self;
-   |       ^^^^^^^ `Self` cannot be formatted with the default formatter
+  --> $DIR/defaults-unsound-62211-2.rs:21:5
+   |
+LL |       type Output: Copy
+   |       ^    ------ required by a bound in this
+   |  _____|
+   | |
+LL | |
+LL | |
+LL | |
+...  |
+LL | |         + From<Self>
+LL | |         + Display = Self;
+   | |___________-------_______^ `Self` cannot be formatted with the default formatter
+   |             |
+   |             required by this bound in `UncheckedCopy::Output`
    |
    = note: in format strings you may be able to use `{:?}` (or {:#?} for pretty-print) instead
 help: consider further restricting `Self`
@@ -55,75 +21,71 @@ help: consider further restricting `Self`
 LL | trait UncheckedCopy: Sized + std::fmt::Display {
    |                            ^^^^^^^^^^^^^^^^^^^
 
-error[E0277]: `T` doesn't implement `std::fmt::Display`
-  --> $DIR/defaults-unsound-62211-2.rs:41:9
-   |
-LL | trait UncheckedCopy: Sized {
-   |       ------------- required by a bound in this
-...
-LL |     + Display = Self;
-   |       ------- required by this bound in `UncheckedCopy`
-...
-LL | impl<T> UncheckedCopy for T {}
-   |         ^^^^^^^^^^^^^ `T` cannot be formatted with the default formatter
-   |
-   = note: in format strings you may be able to use `{:?}` (or {:#?} for pretty-print) instead
-help: consider restricting type parameter `T`
+error[E0277]: the trait bound `Self: std::ops::Deref` is not satisfied
+  --> $DIR/defaults-unsound-62211-2.rs:21:5
+   |
+LL |       type Output: Copy
+   |       ^    ------ required by a bound in this
+   |  _____|
+   | |
+LL | |
+LL | |
+LL | |
+LL | |
+LL | |         + Deref<Target = str>
+   | |           ------------------- required by this bound in `UncheckedCopy::Output`
+LL | |         + AddAssign<&'static str>
+LL | |         + From<Self>
+LL | |         + Display = Self;
+   | |_________________________^ the trait `std::ops::Deref` is not implemented for `Self`
    |
-LL | impl<T: std::fmt::Display> UncheckedCopy for T {}
-   |       ^^^^^^^^^^^^^^^^^^^
-
-error[E0277]: the trait bound `T: Deref` is not satisfied
-  --> $DIR/defaults-unsound-62211-2.rs:41:9
-   |
-LL | trait UncheckedCopy: Sized {
-   |       ------------- required by a bound in this
-...
-LL |     + Deref<Target = str>
-   |       ------------------- required by this bound in `UncheckedCopy`
-...
-LL | impl<T> UncheckedCopy for T {}
-   |         ^^^^^^^^^^^^^ the trait `Deref` is not implemented for `T`
-   |
-help: consider restricting type parameter `T`
+help: consider further restricting `Self`
    |
-LL | impl<T: Deref> UncheckedCopy for T {}
-   |       ^^^^^^^
+LL | trait UncheckedCopy: Sized + Deref {
+   |                            ^^^^^^^
 
-error[E0277]: cannot add-assign `&'static str` to `T`
-  --> $DIR/defaults-unsound-62211-2.rs:41:9
-   |
-LL | trait UncheckedCopy: Sized {
-   |       ------------- required by a bound in this
-...
-LL |     + AddAssign<&'static str>
-   |       ----------------------- required by this bound in `UncheckedCopy`
-...
-LL | impl<T> UncheckedCopy for T {}
-   |         ^^^^^^^^^^^^^ no implementation for `T += &'static str`
+error[E0277]: cannot add-assign `&'static str` to `Self`
+  --> $DIR/defaults-unsound-62211-2.rs:21:5
+   |
+LL |       type Output: Copy
+   |       ^    ------ required by a bound in this
+   |  _____|
+   | |
+LL | |
+LL | |
+LL | |
+...  |
+LL | |         + AddAssign<&'static str>
+   | |           ----------------------- required by this bound in `UncheckedCopy::Output`
+LL | |         + From<Self>
+LL | |         + Display = Self;
+   | |_________________________^ no implementation for `Self += &'static str`
    |
-help: consider restricting type parameter `T`
+help: consider further restricting `Self`
    |
-LL | impl<T: AddAssign<&'static str>> UncheckedCopy for T {}
-   |       ^^^^^^^^^^^^^^^^^^^^^^^^^
+LL | trait UncheckedCopy: Sized + std::ops::AddAssign<&'static str> {
+   |                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error[E0277]: the trait bound `T: Copy` is not satisfied
-  --> $DIR/defaults-unsound-62211-2.rs:41:9
-   |
-LL | trait UncheckedCopy: Sized {
-   |       ------------- required by a bound in this
-...
-LL |     type Output: Copy
-   |                  ---- required by this bound in `UncheckedCopy`
-...
-LL | impl<T> UncheckedCopy for T {}
-   |         ^^^^^^^^^^^^^ the trait `Copy` is not implemented for `T`
+error[E0277]: the trait bound `Self: std::marker::Copy` is not satisfied
+  --> $DIR/defaults-unsound-62211-2.rs:21:5
+   |
+LL |       type Output: Copy
+   |       ^            ---- required by this bound in `UncheckedCopy::Output`
+   |  _____|
+   | |
+LL | |
+LL | |
+LL | |
+...  |
+LL | |         + From<Self>
+LL | |         + Display = Self;
+   | |_________________________^ the trait `std::marker::Copy` is not implemented for `Self`
    |
-help: consider restricting type parameter `T`
+help: consider further restricting `Self`
    |
-LL | impl<T: Copy> UncheckedCopy for T {}
-   |       ^^^^^^
+LL | trait UncheckedCopy: Sized + std::marker::Copy {
+   |                            ^^^^^^^^^^^^^^^^^^^
 
-error: aborting due to 8 previous errors
+error: aborting due to 4 previous errors
 
 For more information about this error, try `rustc --explain E0277`.
diff --git a/src/test/ui/associated-types/defaults-wf.rs b/src/test/ui/associated-types/defaults-wf.rs
new file mode 100644
index 00000000000..99b51250334
--- /dev/null
+++ b/src/test/ui/associated-types/defaults-wf.rs
@@ -0,0 +1,11 @@
+// Check that associated type defaults are wf checked.
+
+#![feature(associated_type_defaults)]
+
+// Default types must always be wf
+trait Tr3 {
+    type Ty = Vec<[u8]>;
+    //~^ ERROR the size for values of type `[u8]` cannot be known at compilation time
+}
+
+fn main() {}
diff --git a/src/test/ui/associated-types/defaults-wf.stderr b/src/test/ui/associated-types/defaults-wf.stderr
new file mode 100644
index 00000000000..aeb7b6cae19
--- /dev/null
+++ b/src/test/ui/associated-types/defaults-wf.stderr
@@ -0,0 +1,16 @@
+error[E0277]: the size for values of type `[u8]` cannot be known at compilation time
+  --> $DIR/defaults-wf.rs:7:5
+   |
+LL |     type Ty = Vec<[u8]>;
+   |     ^^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
+   | 
+  ::: $SRC_DIR/liballoc/vec.rs:LL:COL
+   |
+LL | pub struct Vec<T> {
+   |                - required by this bound in `std::vec::Vec`
+   |
+   = help: the trait `std::marker::Sized` is not implemented for `[u8]`
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0277`.
diff --git a/src/test/ui/associated-types/issue-43924.rs b/src/test/ui/associated-types/issue-43924.rs
index 26f1183c6bd..6a63b3e0936 100644
--- a/src/test/ui/associated-types/issue-43924.rs
+++ b/src/test/ui/associated-types/issue-43924.rs
@@ -4,12 +4,13 @@
 // type-checked.
 
 trait Foo<T: Default + ToString> {
-    type Out: Default + ToString + ?Sized = dyn ToString;  //~ error: not satisfied
+    type Out: Default + ToString + ?Sized = dyn ToString;  //~ ERROR not satisfied
 }
 
-impl Foo<u32> for () {}  //~ error: not satisfied
-impl Foo<u64> for () {}  //~ error: not satisfied
+impl Foo<u32> for () {}
+impl Foo<u64> for () {}
 
 fn main() {
     assert_eq!(<() as Foo<u32>>::Out::default().to_string(), "false");
+    //~^ ERROR no function or associated item named `default` found for trait object
 }
diff --git a/src/test/ui/associated-types/issue-43924.stderr b/src/test/ui/associated-types/issue-43924.stderr
index 661730bcd75..9bcedb05ed4 100644
--- a/src/test/ui/associated-types/issue-43924.stderr
+++ b/src/test/ui/associated-types/issue-43924.stderr
@@ -1,33 +1,19 @@
-error[E0277]: the trait bound `(dyn ToString + 'static): Default` is not satisfied
-  --> $DIR/issue-43924.rs:7:15
+error[E0277]: the trait bound `(dyn std::string::ToString + 'static): std::default::Default` is not satisfied
+  --> $DIR/issue-43924.rs:7:5
    |
-LL | trait Foo<T: Default + ToString> {
-   | -------------------------------- required by `Foo`
 LL |     type Out: Default + ToString + ?Sized = dyn ToString;
-   |               ^^^^^^^ the trait `Default` is not implemented for `(dyn ToString + 'static)`
+   |     ^^^^^^^^^^-------^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |     |         |
+   |     |         required by this bound in `Foo::Out`
+   |     the trait `std::default::Default` is not implemented for `(dyn std::string::ToString + 'static)`
 
-error[E0277]: the trait bound `(dyn ToString + 'static): Default` is not satisfied
-  --> $DIR/issue-43924.rs:10:6
+error[E0599]: no function or associated item named `default` found for trait object `(dyn std::string::ToString + 'static)` in the current scope
+  --> $DIR/issue-43924.rs:14:39
    |
-LL | trait Foo<T: Default + ToString> {
-   |       --- required by a bound in this
-LL |     type Out: Default + ToString + ?Sized = dyn ToString;
-   |               ------- required by this bound in `Foo`
-...
-LL | impl Foo<u32> for () {}
-   |      ^^^^^^^^ the trait `Default` is not implemented for `(dyn ToString + 'static)`
-
-error[E0277]: the trait bound `(dyn ToString + 'static): Default` is not satisfied
-  --> $DIR/issue-43924.rs:11:6
-   |
-LL | trait Foo<T: Default + ToString> {
-   |       --- required by a bound in this
-LL |     type Out: Default + ToString + ?Sized = dyn ToString;
-   |               ------- required by this bound in `Foo`
-...
-LL | impl Foo<u64> for () {}
-   |      ^^^^^^^^ the trait `Default` is not implemented for `(dyn ToString + 'static)`
+LL |     assert_eq!(<() as Foo<u32>>::Out::default().to_string(), "false");
+   |                                       ^^^^^^^ function or associated item not found in `(dyn std::string::ToString + 'static)`
 
-error: aborting due to 3 previous errors
+error: aborting due to 2 previous errors
 
-For more information about this error, try `rustc --explain E0277`.
+Some errors have detailed explanations: E0277, E0599.
+For more information about an error, try `rustc --explain E0277`.
diff --git a/src/test/ui/associated-types/issue-63593.stderr b/src/test/ui/associated-types/issue-63593.stderr
index ddc0bf436f6..16ae07687e2 100644
--- a/src/test/ui/associated-types/issue-63593.stderr
+++ b/src/test/ui/associated-types/issue-63593.stderr
@@ -1,10 +1,11 @@
 error[E0277]: the size for values of type `Self` cannot be known at compilation time
   --> $DIR/issue-63593.rs:9:5
    |
-LL | trait MyTrait {
-   | ------------- required by `MyTrait`
 LL |     type This = Self;
-   |     ^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
+   |     ^^^^^^^^^^^^^^^^^
+   |     |
+   |     doesn't have a size known at compile-time
+   |     required by this bound in `MyTrait::This`
    |
 help: consider further restricting `Self`
    |
diff --git a/src/test/ui/associated-types/issue-65774-1.rs b/src/test/ui/associated-types/issue-65774-1.rs
index 0ffd6cc2cf2..9345140558b 100644
--- a/src/test/ui/associated-types/issue-65774-1.rs
+++ b/src/test/ui/associated-types/issue-65774-1.rs
@@ -14,7 +14,6 @@ trait MPU {
 struct S;
 
 impl MPU for S { }
-//~^ ERROR the trait bound `T: MyDisplay` is not satisfied
 
 trait MyWrite {
     fn my_write(&self, _: &dyn MyDisplay) { }
@@ -43,6 +42,7 @@ impl ProcessType for Process {
         // FulfillmentError(Obligation(predicate=Binder(TraitPredicate(<T as MyDisplay>)),
         // depth=1),Unimplemented)
         let closure = |config: &mut <S as MPU>::MpuConfig| writer.my_write(&config);
+        //~^ ERROR the trait bound `T: MyDisplay` is not satisfied
         closure(valref);
     }
 }
diff --git a/src/test/ui/associated-types/issue-65774-1.stderr b/src/test/ui/associated-types/issue-65774-1.stderr
index 72f47df5d80..f644eb5a1f4 100644
--- a/src/test/ui/associated-types/issue-65774-1.stderr
+++ b/src/test/ui/associated-types/issue-65774-1.stderr
@@ -1,21 +1,20 @@
 error[E0277]: the trait bound `T: MyDisplay` is not satisfied
-  --> $DIR/issue-65774-1.rs:10:21
+  --> $DIR/issue-65774-1.rs:10:5
    |
-LL | trait MPU {
-   | --------- required by `MPU`
 LL |     type MpuConfig: MyDisplay = T;
-   |                     ^^^^^^^^^ the trait `MyDisplay` is not implemented for `T`
+   |     ^^^^^^^^^^^^^^^^---------^^^^^
+   |     |               |
+   |     |               required by this bound in `MPU::MpuConfig`
+   |     the trait `MyDisplay` is not implemented for `T`
 
 error[E0277]: the trait bound `T: MyDisplay` is not satisfied
-  --> $DIR/issue-65774-1.rs:16:6
+  --> $DIR/issue-65774-1.rs:44:76
    |
-LL | trait MPU {
-   |       --- required by a bound in this
-LL |     type MpuConfig: MyDisplay = T;
-   |                     --------- required by this bound in `MPU`
-...
-LL | impl MPU for S { }
-   |      ^^^ the trait `MyDisplay` is not implemented for `T`
+LL |         let closure = |config: &mut <S as MPU>::MpuConfig| writer.my_write(&config);
+   |                                                                            ^^^^^^^ the trait `MyDisplay` is not implemented for `T`
+   |
+   = note: required because of the requirements on the impl of `MyDisplay` for `&mut T`
+   = note: required for the cast to the object type `dyn MyDisplay`
 
 error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/associated-types/issue-65774-2.rs b/src/test/ui/associated-types/issue-65774-2.rs
index 31e203a81d3..171e0893b47 100644
--- a/src/test/ui/associated-types/issue-65774-2.rs
+++ b/src/test/ui/associated-types/issue-65774-2.rs
@@ -14,7 +14,6 @@ trait MPU {
 struct S;
 
 impl MPU for S { }
-//~^ ERROR the trait bound `T: MyDisplay` is not satisfied
 
 trait MyWrite {
     fn my_write(&self, _: &dyn MyDisplay) { }
@@ -38,6 +37,7 @@ impl ProcessType for Process {
         // // `Unimplemented` selecting `Binder(<T as MyDisplay>)` during codegen
         //
         writer.my_write(valref)
+        //~^ ERROR the trait bound `T: MyDisplay` is not satisfied
 
         // This one causes the ICE:
         // FulfillmentError(Obligation(predicate=Binder(TraitPredicate(<T as MyDisplay>)),
diff --git a/src/test/ui/associated-types/issue-65774-2.stderr b/src/test/ui/associated-types/issue-65774-2.stderr
index aef70885af3..572a9cf1909 100644
--- a/src/test/ui/associated-types/issue-65774-2.stderr
+++ b/src/test/ui/associated-types/issue-65774-2.stderr
@@ -1,21 +1,19 @@
 error[E0277]: the trait bound `T: MyDisplay` is not satisfied
-  --> $DIR/issue-65774-2.rs:10:21
+  --> $DIR/issue-65774-2.rs:10:5
    |
-LL | trait MPU {
-   | --------- required by `MPU`
 LL |     type MpuConfig: MyDisplay = T;
-   |                     ^^^^^^^^^ the trait `MyDisplay` is not implemented for `T`
+   |     ^^^^^^^^^^^^^^^^---------^^^^^
+   |     |               |
+   |     |               required by this bound in `MPU::MpuConfig`
+   |     the trait `MyDisplay` is not implemented for `T`
 
 error[E0277]: the trait bound `T: MyDisplay` is not satisfied
-  --> $DIR/issue-65774-2.rs:16:6
+  --> $DIR/issue-65774-2.rs:39:25
    |
-LL | trait MPU {
-   |       --- required by a bound in this
-LL |     type MpuConfig: MyDisplay = T;
-   |                     --------- required by this bound in `MPU`
-...
-LL | impl MPU for S { }
-   |      ^^^ the trait `MyDisplay` is not implemented for `T`
+LL |         writer.my_write(valref)
+   |                         ^^^^^^ the trait `MyDisplay` is not implemented for `T`
+   |
+   = note: required for the cast to the object type `dyn MyDisplay`
 
 error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/associated-types/issue-72806.rs b/src/test/ui/associated-types/issue-72806.rs
index ae63781d568..94758250346 100644
--- a/src/test/ui/associated-types/issue-72806.rs
+++ b/src/test/ui/associated-types/issue-72806.rs
@@ -9,9 +9,10 @@ trait Bar2 {
 struct Foo;
 struct Foo2;
 
-impl Bar for Foo {  //~ ERROR type mismatch resolving `<Foo2 as Bar2>::Ok == char`
+impl Bar for Foo {
     type Ok = ();
     type Sibling = Foo2;
+    //~^ ERROR type mismatch resolving `<Foo2 as Bar2>::Ok == char`
 }
 impl Bar2 for Foo2 {
     type Ok = u32;
diff --git a/src/test/ui/associated-types/issue-72806.stderr b/src/test/ui/associated-types/issue-72806.stderr
index 03a6565848d..23fabbee1c5 100644
--- a/src/test/ui/associated-types/issue-72806.stderr
+++ b/src/test/ui/associated-types/issue-72806.stderr
@@ -1,8 +1,11 @@
 error[E0271]: type mismatch resolving `<Foo2 as Bar2>::Ok == char`
-  --> $DIR/issue-72806.rs:12:6
+  --> $DIR/issue-72806.rs:14:5
    |
-LL | impl Bar for Foo {
-   |      ^^^ expected `u32`, found `char`
+LL |     type Sibling: Bar2<Ok=char>;
+   |                        ------- required by this bound in `Bar::Sibling`
+...
+LL |     type Sibling = Foo2;
+   |     ^^^^^^^^^^^^^^^^^^^^ expected `char`, found `u32`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/associated-types/point-at-type-on-obligation-failure-2.rs b/src/test/ui/associated-types/point-at-type-on-obligation-failure-2.rs
index 67b7c78071c..4bd3ccab834 100644
--- a/src/test/ui/associated-types/point-at-type-on-obligation-failure-2.rs
+++ b/src/test/ui/associated-types/point-at-type-on-obligation-failure-2.rs
@@ -5,7 +5,9 @@ trait Foo {
 }
 
 impl Foo for () {
-    type Assoc = bool; //~ ERROR the trait bound `bool: Bar` is not satisfied
+    // Doesn't error because we abort compilation after the errors below.
+    // See point-at-type-on-obligation-failure-3.rs
+    type Assoc = bool;
 }
 
 trait Baz where Self::Assoc: Bar {
diff --git a/src/test/ui/associated-types/point-at-type-on-obligation-failure-2.stderr b/src/test/ui/associated-types/point-at-type-on-obligation-failure-2.stderr
index 3118a9c5352..f4971105499 100644
--- a/src/test/ui/associated-types/point-at-type-on-obligation-failure-2.stderr
+++ b/src/test/ui/associated-types/point-at-type-on-obligation-failure-2.stderr
@@ -1,16 +1,5 @@
 error[E0277]: the trait bound `bool: Bar` is not satisfied
-  --> $DIR/point-at-type-on-obligation-failure-2.rs:8:18
-   |
-LL | trait Foo {
-   |       --- required by a bound in this
-LL |     type Assoc: Bar;
-   |                 --- required by this bound in `Foo`
-...
-LL |     type Assoc = bool;
-   |                  ^^^^ the trait `Bar` is not implemented for `bool`
-
-error[E0277]: the trait bound `bool: Bar` is not satisfied
-  --> $DIR/point-at-type-on-obligation-failure-2.rs:16:18
+  --> $DIR/point-at-type-on-obligation-failure-2.rs:18:18
    |
 LL | trait Baz where Self::Assoc: Bar {
    |                              --- required by this bound in `Baz`
@@ -19,7 +8,7 @@ LL |     type Assoc = bool;
    |                  ^^^^ the trait `Bar` is not implemented for `bool`
 
 error[E0277]: the trait bound `bool: Bar` is not satisfied
-  --> $DIR/point-at-type-on-obligation-failure-2.rs:24:18
+  --> $DIR/point-at-type-on-obligation-failure-2.rs:26:18
    |
 LL | trait Bat where <Self as Bat>::Assoc: Bar {
    |                                       --- required by this bound in `Bat`
@@ -27,6 +16,6 @@ LL | trait Bat where <Self as Bat>::Assoc: Bar {
 LL |     type Assoc = bool;
    |                  ^^^^ the trait `Bar` is not implemented for `bool`
 
-error: aborting due to 3 previous errors
+error: aborting due to 2 previous errors
 
 For more information about this error, try `rustc --explain E0277`.
diff --git a/src/test/ui/associated-types/point-at-type-on-obligation-failure-3.rs b/src/test/ui/associated-types/point-at-type-on-obligation-failure-3.rs
new file mode 100644
index 00000000000..9360d96f05e
--- /dev/null
+++ b/src/test/ui/associated-types/point-at-type-on-obligation-failure-3.rs
@@ -0,0 +1,11 @@
+trait Bar {}
+
+trait Foo {
+    type Assoc: Bar;
+}
+
+impl Foo for () {
+    type Assoc = bool; //~ ERROR the trait bound `bool: Bar` is not satisfied
+}
+
+fn main() {}
diff --git a/src/test/ui/associated-types/point-at-type-on-obligation-failure-3.stderr b/src/test/ui/associated-types/point-at-type-on-obligation-failure-3.stderr
new file mode 100644
index 00000000000..6ab3d94e102
--- /dev/null
+++ b/src/test/ui/associated-types/point-at-type-on-obligation-failure-3.stderr
@@ -0,0 +1,12 @@
+error[E0277]: the trait bound `bool: Bar` is not satisfied
+  --> $DIR/point-at-type-on-obligation-failure-3.rs:8:5
+   |
+LL |     type Assoc: Bar;
+   |                 --- required by this bound in `Foo::Assoc`
+...
+LL |     type Assoc = bool;
+   |     ^^^^^^^^^^^^^^^^^^ the trait `Bar` is not implemented for `bool`
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0277`.
diff --git a/src/test/ui/associated-types/point-at-type-on-obligation-failure.rs b/src/test/ui/associated-types/point-at-type-on-obligation-failure.rs
index dc43dbaf54b..66666006887 100644
--- a/src/test/ui/associated-types/point-at-type-on-obligation-failure.rs
+++ b/src/test/ui/associated-types/point-at-type-on-obligation-failure.rs
@@ -10,8 +10,9 @@ struct Foo;
 struct Foo2;
 
 impl Bar for Foo {
-    type Ok = ();  //~ ERROR type mismatch resolving `<Foo2 as Bar2>::Ok == ()`
+    type Ok = ();
     type Sibling = Foo2;
+    //~^ ERROR type mismatch resolving `<Foo2 as Bar2>::Ok == ()`
 }
 impl Bar2 for Foo2 {
     type Ok = u32;
diff --git a/src/test/ui/associated-types/point-at-type-on-obligation-failure.stderr b/src/test/ui/associated-types/point-at-type-on-obligation-failure.stderr
index 818702b7afe..7417a5aa3d4 100644
--- a/src/test/ui/associated-types/point-at-type-on-obligation-failure.stderr
+++ b/src/test/ui/associated-types/point-at-type-on-obligation-failure.stderr
@@ -1,8 +1,11 @@
 error[E0271]: type mismatch resolving `<Foo2 as Bar2>::Ok == ()`
-  --> $DIR/point-at-type-on-obligation-failure.rs:13:15
+  --> $DIR/point-at-type-on-obligation-failure.rs:14:5
    |
-LL |     type Ok = ();
-   |               ^^ expected `u32`, found `()`
+LL |     type Sibling: Bar2<Ok=Self::Ok>;
+   |                        ----------- required by this bound in `Bar::Sibling`
+...
+LL |     type Sibling = Foo2;
+   |     ^^^^^^^^^^^^^^^^^^^^ expected `()`, found `u32`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/chalkify/impl_wf.rs b/src/test/ui/chalkify/impl_wf.rs
index 465eb10241e..66f57c2d110 100644
--- a/src/test/ui/chalkify/impl_wf.rs
+++ b/src/test/ui/chalkify/impl_wf.rs
@@ -15,19 +15,6 @@ impl Foo for str { }
 // Implicit `T: Sized` bound.
 impl<T> Foo for Option<T> { }
 
-impl Bar for () {
-    type Item = i32;
-}
-
-impl<T> Bar for Option<T> {
-    type Item = Option<T>;
-}
-
-impl Bar for f32 {
-    type Item = f32;
-    //~^ ERROR the trait bound `f32: Foo` is not satisfied
-}
-
 trait Baz<U: ?Sized> where U: Foo { }
 
 impl Baz<i32> for i32 { }
diff --git a/src/test/ui/chalkify/impl_wf.stderr b/src/test/ui/chalkify/impl_wf.stderr
index 4ca5ae472f2..24c7f0d82bd 100644
--- a/src/test/ui/chalkify/impl_wf.stderr
+++ b/src/test/ui/chalkify/impl_wf.stderr
@@ -10,18 +10,7 @@ LL | impl Foo for str { }
    = help: the trait `Sized` is not implemented for `str`
 
 error[E0277]: the trait bound `f32: Foo` is not satisfied
-  --> $DIR/impl_wf.rs:27:17
-   |
-LL | trait Bar {
-   |       --- required by a bound in this
-LL |     type Item: Foo;
-   |                --- required by this bound in `Bar`
-...
-LL |     type Item = f32;
-   |                 ^^^ the trait `Foo` is not implemented for `f32`
-
-error[E0277]: the trait bound `f32: Foo` is not satisfied
-  --> $DIR/impl_wf.rs:35:6
+  --> $DIR/impl_wf.rs:22:6
    |
 LL | trait Baz<U: ?Sized> where U: Foo { }
    |                               --- required by this bound in `Baz`
@@ -29,6 +18,6 @@ LL | trait Baz<U: ?Sized> where U: Foo { }
 LL | impl Baz<f32> for f32 { }
    |      ^^^^^^^^ the trait `Foo` is not implemented for `f32`
 
-error: aborting due to 3 previous errors
+error: aborting due to 2 previous errors
 
 For more information about this error, try `rustc --explain E0277`.
diff --git a/src/test/ui/chalkify/impl_wf_2.rs b/src/test/ui/chalkify/impl_wf_2.rs
new file mode 100644
index 00000000000..758a7185e39
--- /dev/null
+++ b/src/test/ui/chalkify/impl_wf_2.rs
@@ -0,0 +1,33 @@
+// Split out of impl_wf.rs to work around rust aborting compilation early
+
+// compile-flags: -Z chalk
+
+trait Foo: Sized { }
+
+trait Bar {
+    type Item: Foo;
+}
+
+impl Foo for i32 { }
+
+// Implicit `T: Sized` bound.
+impl<T> Foo for Option<T> { }
+
+impl Bar for () {
+    type Item = i32;
+}
+
+impl<T> Bar for Option<T> {
+    type Item = Option<T>;
+}
+
+impl Bar for f32 {
+    type Item = f32;
+    //~^ ERROR the trait bound `f32: Foo` is not satisfied
+}
+
+trait Baz<U: ?Sized> where U: Foo { }
+
+impl Baz<i32> for i32 { }
+
+fn main() {}
diff --git a/src/test/ui/chalkify/impl_wf_2.stderr b/src/test/ui/chalkify/impl_wf_2.stderr
new file mode 100644
index 00000000000..1da2144c0a5
--- /dev/null
+++ b/src/test/ui/chalkify/impl_wf_2.stderr
@@ -0,0 +1,12 @@
+error[E0277]: the trait bound `f32: Foo` is not satisfied
+  --> $DIR/impl_wf_2.rs:25:5
+   |
+LL |     type Item: Foo;
+   |                --- required by this bound in `Bar::Item`
+...
+LL |     type Item = f32;
+   |     ^^^^^^^^^^^^^^^^ the trait `Foo` is not implemented for `f32`
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0277`.
diff --git a/src/test/ui/feature-gates/feature-gate-associated_type_bounds.rs b/src/test/ui/feature-gates/feature-gate-associated_type_bounds.rs
index 9bce274027e..c5c8c5c1eca 100644
--- a/src/test/ui/feature-gates/feature-gate-associated_type_bounds.rs
+++ b/src/test/ui/feature-gates/feature-gate-associated_type_bounds.rs
@@ -14,6 +14,7 @@ impl Tr1 for S1 { type As1 = S2; }
 trait _Tr3 {
     type A: Iterator<Item: Copy>;
     //~^ ERROR associated type bounds are unstable
+    //~| ERROR the trait bound `<<Self as _Tr3>::A as std::iter::Iterator>::Item: std::marker::Copy` is not satisfied
 
     type B: Iterator<Item: 'static>;
     //~^ ERROR associated type bounds are unstable
diff --git a/src/test/ui/feature-gates/feature-gate-associated_type_bounds.stderr b/src/test/ui/feature-gates/feature-gate-associated_type_bounds.stderr
index 7f2704e1bc3..db78e287d65 100644
--- a/src/test/ui/feature-gates/feature-gate-associated_type_bounds.stderr
+++ b/src/test/ui/feature-gates/feature-gate-associated_type_bounds.stderr
@@ -8,7 +8,7 @@ LL |     type A: Iterator<Item: Copy>;
    = help: add `#![feature(associated_type_bounds)]` to the crate attributes to enable
 
 error[E0658]: associated type bounds are unstable
-  --> $DIR/feature-gate-associated_type_bounds.rs:18:22
+  --> $DIR/feature-gate-associated_type_bounds.rs:19:22
    |
 LL |     type B: Iterator<Item: 'static>;
    |                      ^^^^^^^^^^^^^
@@ -17,7 +17,7 @@ LL |     type B: Iterator<Item: 'static>;
    = help: add `#![feature(associated_type_bounds)]` to the crate attributes to enable
 
 error[E0658]: associated type bounds are unstable
-  --> $DIR/feature-gate-associated_type_bounds.rs:22:20
+  --> $DIR/feature-gate-associated_type_bounds.rs:23:20
    |
 LL | struct _St1<T: Tr1<As1: Tr2>> {
    |                    ^^^^^^^^
@@ -26,7 +26,7 @@ LL | struct _St1<T: Tr1<As1: Tr2>> {
    = help: add `#![feature(associated_type_bounds)]` to the crate attributes to enable
 
 error[E0658]: associated type bounds are unstable
-  --> $DIR/feature-gate-associated_type_bounds.rs:29:18
+  --> $DIR/feature-gate-associated_type_bounds.rs:30:18
    |
 LL | enum _En1<T: Tr1<As1: Tr2>> {
    |                  ^^^^^^^^
@@ -35,7 +35,7 @@ LL | enum _En1<T: Tr1<As1: Tr2>> {
    = help: add `#![feature(associated_type_bounds)]` to the crate attributes to enable
 
 error[E0658]: associated type bounds are unstable
-  --> $DIR/feature-gate-associated_type_bounds.rs:36:19
+  --> $DIR/feature-gate-associated_type_bounds.rs:37:19
    |
 LL | union _Un1<T: Tr1<As1: Tr2>> {
    |                   ^^^^^^^^
@@ -44,7 +44,7 @@ LL | union _Un1<T: Tr1<As1: Tr2>> {
    = help: add `#![feature(associated_type_bounds)]` to the crate attributes to enable
 
 error[E0658]: associated type bounds are unstable
-  --> $DIR/feature-gate-associated_type_bounds.rs:43:37
+  --> $DIR/feature-gate-associated_type_bounds.rs:44:37
    |
 LL | type _TaWhere1<T> where T: Iterator<Item: Copy> = T;
    |                                     ^^^^^^^^^^
@@ -53,7 +53,7 @@ LL | type _TaWhere1<T> where T: Iterator<Item: Copy> = T;
    = help: add `#![feature(associated_type_bounds)]` to the crate attributes to enable
 
 error[E0658]: associated type bounds are unstable
-  --> $DIR/feature-gate-associated_type_bounds.rs:46:22
+  --> $DIR/feature-gate-associated_type_bounds.rs:47:22
    |
 LL | fn _apit(_: impl Tr1<As1: Copy>) {}
    |                      ^^^^^^^^^
@@ -62,7 +62,7 @@ LL | fn _apit(_: impl Tr1<As1: Copy>) {}
    = help: add `#![feature(associated_type_bounds)]` to the crate attributes to enable
 
 error[E0658]: associated type bounds are unstable
-  --> $DIR/feature-gate-associated_type_bounds.rs:48:26
+  --> $DIR/feature-gate-associated_type_bounds.rs:49:26
    |
 LL | fn _apit_dyn(_: &dyn Tr1<As1: Copy>) {}
    |                          ^^^^^^^^^
@@ -71,7 +71,7 @@ LL | fn _apit_dyn(_: &dyn Tr1<As1: Copy>) {}
    = help: add `#![feature(associated_type_bounds)]` to the crate attributes to enable
 
 error[E0658]: associated type bounds are unstable
-  --> $DIR/feature-gate-associated_type_bounds.rs:51:24
+  --> $DIR/feature-gate-associated_type_bounds.rs:52:24
    |
 LL | fn _rpit() -> impl Tr1<As1: Copy> { S1 }
    |                        ^^^^^^^^^
@@ -80,7 +80,7 @@ LL | fn _rpit() -> impl Tr1<As1: Copy> { S1 }
    = help: add `#![feature(associated_type_bounds)]` to the crate attributes to enable
 
 error[E0658]: associated type bounds are unstable
-  --> $DIR/feature-gate-associated_type_bounds.rs:54:31
+  --> $DIR/feature-gate-associated_type_bounds.rs:55:31
    |
 LL | fn _rpit_dyn() -> Box<dyn Tr1<As1: Copy>> { Box::new(S1) }
    |                               ^^^^^^^^^
@@ -89,7 +89,7 @@ LL | fn _rpit_dyn() -> Box<dyn Tr1<As1: Copy>> { Box::new(S1) }
    = help: add `#![feature(associated_type_bounds)]` to the crate attributes to enable
 
 error[E0658]: associated type bounds are unstable
-  --> $DIR/feature-gate-associated_type_bounds.rs:57:23
+  --> $DIR/feature-gate-associated_type_bounds.rs:58:23
    |
 LL | const _cdef: impl Tr1<As1: Copy> = S1;
    |                       ^^^^^^^^^
@@ -98,7 +98,7 @@ LL | const _cdef: impl Tr1<As1: Copy> = S1;
    = help: add `#![feature(associated_type_bounds)]` to the crate attributes to enable
 
 error[E0658]: associated type bounds are unstable
-  --> $DIR/feature-gate-associated_type_bounds.rs:63:24
+  --> $DIR/feature-gate-associated_type_bounds.rs:64:24
    |
 LL | static _sdef: impl Tr1<As1: Copy> = S1;
    |                        ^^^^^^^^^
@@ -107,7 +107,7 @@ LL | static _sdef: impl Tr1<As1: Copy> = S1;
    = help: add `#![feature(associated_type_bounds)]` to the crate attributes to enable
 
 error[E0658]: associated type bounds are unstable
-  --> $DIR/feature-gate-associated_type_bounds.rs:70:21
+  --> $DIR/feature-gate-associated_type_bounds.rs:71:21
    |
 LL |     let _: impl Tr1<As1: Copy> = S1;
    |                     ^^^^^^^^^
@@ -116,7 +116,7 @@ LL |     let _: impl Tr1<As1: Copy> = S1;
    = help: add `#![feature(associated_type_bounds)]` to the crate attributes to enable
 
 error[E0562]: `impl Trait` not allowed outside of function and inherent method return types
-  --> $DIR/feature-gate-associated_type_bounds.rs:57:14
+  --> $DIR/feature-gate-associated_type_bounds.rs:58:14
    |
 LL | const _cdef: impl Tr1<As1: Copy> = S1;
    |              ^^^^^^^^^^^^^^^^^^^
@@ -124,7 +124,7 @@ LL | const _cdef: impl Tr1<As1: Copy> = S1;
    = help: add `#![feature(impl_trait_in_bindings)]` to the crate attributes to enable
 
 error[E0562]: `impl Trait` not allowed outside of function and inherent method return types
-  --> $DIR/feature-gate-associated_type_bounds.rs:63:15
+  --> $DIR/feature-gate-associated_type_bounds.rs:64:15
    |
 LL | static _sdef: impl Tr1<As1: Copy> = S1;
    |               ^^^^^^^^^^^^^^^^^^^
@@ -132,14 +132,30 @@ LL | static _sdef: impl Tr1<As1: Copy> = S1;
    = help: add `#![feature(impl_trait_in_bindings)]` to the crate attributes to enable
 
 error[E0562]: `impl Trait` not allowed outside of function and inherent method return types
-  --> $DIR/feature-gate-associated_type_bounds.rs:70:12
+  --> $DIR/feature-gate-associated_type_bounds.rs:71:12
    |
 LL |     let _: impl Tr1<As1: Copy> = S1;
    |            ^^^^^^^^^^^^^^^^^^^
    |
    = help: add `#![feature(impl_trait_in_bindings)]` to the crate attributes to enable
 
-error: aborting due to 16 previous errors
+error[E0277]: the trait bound `<<Self as _Tr3>::A as std::iter::Iterator>::Item: std::marker::Copy` is not satisfied
+  --> $DIR/feature-gate-associated_type_bounds.rs:15:28
+   |
+LL |     type A: Iterator<Item: Copy>;
+   |                            ^^^^ the trait `std::marker::Copy` is not implemented for `<<Self as _Tr3>::A as std::iter::Iterator>::Item`
+   | 
+  ::: $SRC_DIR/libcore/marker.rs:LL:COL
+   |
+LL | pub trait Copy: Clone {
+   | --------------------- required by this bound in `std::marker::Copy`
+   |
+help: consider further restricting the associated type
+   |
+LL | trait _Tr3 where <<Self as _Tr3>::A as std::iter::Iterator>::Item: std::marker::Copy {
+   |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 17 previous errors
 
-Some errors have detailed explanations: E0562, E0658.
-For more information about an error, try `rustc --explain E0562`.
+Some errors have detailed explanations: E0277, E0562, E0658.
+For more information about an error, try `rustc --explain E0277`.
diff --git a/src/test/ui/generator/sized-yield.stderr b/src/test/ui/generator/sized-yield.stderr
index 2bcf66dbeae..e49dc91ec66 100644
--- a/src/test/ui/generator/sized-yield.stderr
+++ b/src/test/ui/generator/sized-yield.stderr
@@ -16,6 +16,11 @@ error[E0277]: the size for values of type `str` cannot be known at compilation t
    |
 LL |    Pin::new(&mut gen).resume(());
    |                       ^^^^^^ doesn't have a size known at compile-time
+   | 
+  ::: $SRC_DIR/libcore/ops/generator.rs:LL:COL
+   |
+LL | pub enum GeneratorState<Y, R> {
+   |                         - required by this bound in `std::ops::GeneratorState`
    |
    = help: the trait `Sized` is not implemented for `str`
 
diff --git a/src/test/ui/generic-associated-types/issue-68641-check-gat-bounds.stderr b/src/test/ui/generic-associated-types/issue-68641-check-gat-bounds.stderr
index 6ba79dd5437..b380f0da2ea 100644
--- a/src/test/ui/generic-associated-types/issue-68641-check-gat-bounds.stderr
+++ b/src/test/ui/generic-associated-types/issue-68641-check-gat-bounds.stderr
@@ -11,7 +11,7 @@ error[E0277]: the trait bound `T: Copy` is not satisfied
   --> $DIR/issue-68641-check-gat-bounds.rs:15:5
    |
 LL |     type Item<'a>: Copy;
-   |     -------------------- required by `UnsafeCopy::Item`
+   |                    ---- required by this bound in `UnsafeCopy::Item`
 ...
 LL |     type Item<'a> = T;
    |     ^^^^^^^^^^^^^^^^^^ the trait `Copy` is not implemented for `T`
diff --git a/src/test/ui/generic-associated-types/issue-68642-broken-llvm-ir.stderr b/src/test/ui/generic-associated-types/issue-68642-broken-llvm-ir.stderr
index 15a66e25b19..61950478c32 100644
--- a/src/test/ui/generic-associated-types/issue-68642-broken-llvm-ir.stderr
+++ b/src/test/ui/generic-associated-types/issue-68642-broken-llvm-ir.stderr
@@ -11,7 +11,7 @@ error[E0277]: expected a `Fn<()>` closure, found `T`
   --> $DIR/issue-68642-broken-llvm-ir.rs:15:5
    |
 LL |     type F<'a>: Fn() -> u32;
-   |     ------------------------ required by `Fun::F`
+   |                 ----------- required by this bound in `Fun::F`
 ...
 LL |     type F<'a> = Self;
    |     ^^^^^^^^^^^^^^^^^^ expected an `Fn<()>` closure, found `T`
diff --git a/src/test/ui/generic-associated-types/issue-68643-broken-mir.stderr b/src/test/ui/generic-associated-types/issue-68643-broken-mir.stderr
index 9b2ddb23267..13980618987 100644
--- a/src/test/ui/generic-associated-types/issue-68643-broken-mir.stderr
+++ b/src/test/ui/generic-associated-types/issue-68643-broken-mir.stderr
@@ -11,7 +11,7 @@ error[E0277]: expected a `Fn<()>` closure, found `T`
   --> $DIR/issue-68643-broken-mir.rs:15:5
    |
 LL |     type F<'a>: Fn() -> u32;
-   |     ------------------------ required by `Fun::F`
+   |                 ----------- required by this bound in `Fun::F`
 ...
 LL |     type F<'a> = Self;
    |     ^^^^^^^^^^^^^^^^^^ expected an `Fn<()>` closure, found `T`
diff --git a/src/test/ui/generic-associated-types/issue-68644-codegen-selection.stderr b/src/test/ui/generic-associated-types/issue-68644-codegen-selection.stderr
index f7bfab35052..81124251469 100644
--- a/src/test/ui/generic-associated-types/issue-68644-codegen-selection.stderr
+++ b/src/test/ui/generic-associated-types/issue-68644-codegen-selection.stderr
@@ -11,7 +11,7 @@ error[E0277]: expected a `Fn<()>` closure, found `T`
   --> $DIR/issue-68644-codegen-selection.rs:15:5
    |
 LL |     type F<'a>: Fn() -> u32;
-   |     ------------------------ required by `Fun::F`
+   |                 ----------- required by this bound in `Fun::F`
 ...
 LL |     type F<'a> = Self;
    |     ^^^^^^^^^^^^^^^^^^ expected an `Fn<()>` closure, found `T`
diff --git a/src/test/ui/generic-associated-types/issue-68645-codegen-fulfillment.stderr b/src/test/ui/generic-associated-types/issue-68645-codegen-fulfillment.stderr
index 6c2d330a19a..22f50b39498 100644
--- a/src/test/ui/generic-associated-types/issue-68645-codegen-fulfillment.stderr
+++ b/src/test/ui/generic-associated-types/issue-68645-codegen-fulfillment.stderr
@@ -11,7 +11,7 @@ error[E0277]: expected a `Fn<()>` closure, found `T`
   --> $DIR/issue-68645-codegen-fulfillment.rs:15:5
    |
 LL |     type F<'a>: Fn() -> u32;
-   |     ------------------------ required by `Fun::F`
+   |                 ----------- required by this bound in `Fun::F`
 ...
 LL |     type F<'a> = Self;
    |     ^^^^^^^^^^^^^^^^^^ expected an `Fn<()>` closure, found `T`
diff --git a/src/test/ui/generic-associated-types/issue-68656-unsized-values.stderr b/src/test/ui/generic-associated-types/issue-68656-unsized-values.stderr
index a9336151b6a..c4ee2c4e618 100644
--- a/src/test/ui/generic-associated-types/issue-68656-unsized-values.stderr
+++ b/src/test/ui/generic-associated-types/issue-68656-unsized-values.stderr
@@ -11,7 +11,7 @@ error[E0271]: type mismatch resolving `<T as Deref>::Target == T`
   --> $DIR/issue-68656-unsized-values.rs:16:5
    |
 LL |     type Item<'a>: std::ops::Deref<Target = T>;
-   |     ------------------------------------------- required by `UnsafeCopy::Item`
+   |                                    ---------- required by this bound in `UnsafeCopy::Item`
 ...
 LL | impl<T: Copy + std::ops::Deref> UnsafeCopy<T> for T {
    |      - this type parameter
diff --git a/src/test/ui/generic-associated-types/unsatisfied-outlives-bound.rs b/src/test/ui/generic-associated-types/unsatisfied-outlives-bound.rs
index 7510c58d574..d957cae3081 100644
--- a/src/test/ui/generic-associated-types/unsatisfied-outlives-bound.rs
+++ b/src/test/ui/generic-associated-types/unsatisfied-outlives-bound.rs
@@ -7,7 +7,7 @@ trait ATy {
 
 impl<'b> ATy for &'b () {
     type Item<'a> = &'b ();
-    //~^ ERROR does not fulfill the required lifetime
+    //~^ ERROR lifetime bound not satisfied
 }
 
 trait StaticTy {
@@ -16,7 +16,7 @@ trait StaticTy {
 
 impl StaticTy for () {
     type Item<'a> = &'a ();
-    //~^ ERROR does not fulfill the required lifetime
+    //~^ ERROR lifetime bound not satisfied
 }
 
 fn main() {}
diff --git a/src/test/ui/generic-associated-types/unsatisfied-outlives-bound.stderr b/src/test/ui/generic-associated-types/unsatisfied-outlives-bound.stderr
index 5d612284a21..f8b96ef3b8a 100644
--- a/src/test/ui/generic-associated-types/unsatisfied-outlives-bound.stderr
+++ b/src/test/ui/generic-associated-types/unsatisfied-outlives-bound.stderr
@@ -1,23 +1,33 @@
-error[E0477]: the type `&'b ()` does not fulfill the required lifetime
+error[E0478]: lifetime bound not satisfied
   --> $DIR/unsatisfied-outlives-bound.rs:9:5
    |
 LL |     type Item<'a> = &'b ();
    |     ^^^^^^^^^^^^^^^^^^^^^^^
    |
-note: type must outlive the lifetime `'a` as defined on the associated item at 9:15
+note: lifetime parameter instantiated with the lifetime `'b` as defined on the impl at 8:6
+  --> $DIR/unsatisfied-outlives-bound.rs:8:6
+   |
+LL | impl<'b> ATy for &'b () {
+   |      ^^
+note: but lifetime parameter must outlive the lifetime `'a` as defined on the associated item at 9:15
   --> $DIR/unsatisfied-outlives-bound.rs:9:15
    |
 LL |     type Item<'a> = &'b ();
    |               ^^
 
-error[E0477]: the type `&'a ()` does not fulfill the required lifetime
+error[E0478]: lifetime bound not satisfied
   --> $DIR/unsatisfied-outlives-bound.rs:18:5
    |
 LL |     type Item<'a> = &'a ();
    |     ^^^^^^^^^^^^^^^^^^^^^^^
    |
-   = note: type must satisfy the static lifetime
+note: lifetime parameter instantiated with the lifetime `'a` as defined on the associated item at 18:15
+  --> $DIR/unsatisfied-outlives-bound.rs:18:15
+   |
+LL |     type Item<'a> = &'a ();
+   |               ^^
+   = note: but lifetime parameter must outlive the static lifetime
 
 error: aborting due to 2 previous errors
 
-For more information about this error, try `rustc --explain E0477`.
+For more information about this error, try `rustc --explain E0478`.
diff --git a/src/test/ui/inference/cannot-infer-async-enabled-impl-trait-bindings.stderr b/src/test/ui/inference/cannot-infer-async-enabled-impl-trait-bindings.stderr
index b6e3bb190ea..ec03d18924f 100644
--- a/src/test/ui/inference/cannot-infer-async-enabled-impl-trait-bindings.stderr
+++ b/src/test/ui/inference/cannot-infer-async-enabled-impl-trait-bindings.stderr
@@ -7,13 +7,13 @@ LL | #![feature(impl_trait_in_bindings)]
    = note: `#[warn(incomplete_features)]` on by default
    = note: see issue #63065 <https://github.com/rust-lang/rust/issues/63065> for more information
 
-error[E0282]: type annotations needed for `impl Future`
-  --> $DIR/cannot-infer-async-enabled-impl-trait-bindings.rs:13:9
+error[E0282]: type annotations needed for `impl std::future::Future`
+  --> $DIR/cannot-infer-async-enabled-impl-trait-bindings.rs:13:20
    |
 LL |     let fut = async {
    |         --- consider giving `fut` the explicit type `impl Future`, with the type parameters specified
 LL |         make_unit()?;
-   |         ^^^^^^^^^^^^ cannot infer type
+   |                    ^ cannot infer type
 
 error: aborting due to previous error; 1 warning emitted
 
diff --git a/src/test/ui/inference/cannot-infer-async.stderr b/src/test/ui/inference/cannot-infer-async.stderr
index bf31fb85cf6..92a9045f6db 100644
--- a/src/test/ui/inference/cannot-infer-async.stderr
+++ b/src/test/ui/inference/cannot-infer-async.stderr
@@ -1,10 +1,10 @@
 error[E0282]: type annotations needed
-  --> $DIR/cannot-infer-async.rs:11:9
+  --> $DIR/cannot-infer-async.rs:11:20
    |
 LL |     let fut = async {
    |         --- consider giving `fut` a type
 LL |         make_unit()?;
-   |         ^^^^^^^^^^^^ cannot infer type
+   |                    ^ cannot infer type
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/inference/cannot-infer-closure.stderr b/src/test/ui/inference/cannot-infer-closure.stderr
index c26c24f1dc5..d5366e422db 100644
--- a/src/test/ui/inference/cannot-infer-closure.stderr
+++ b/src/test/ui/inference/cannot-infer-closure.stderr
@@ -1,8 +1,8 @@
 error[E0282]: type annotations needed for the closure `fn((), ()) -> std::result::Result<(), _>`
-  --> $DIR/cannot-infer-closure.rs:3:9
+  --> $DIR/cannot-infer-closure.rs:3:15
    |
 LL |         Err(a)?;
-   |         ^^^^^^^ cannot infer type
+   |               ^ cannot infer type
    |
 help: give this closure an explicit return type without `_` placeholders
    |
diff --git a/src/test/ui/issues/issue-20605.stderr b/src/test/ui/issues/issue-20605.stderr
index e8d16a55e92..25fa575fc60 100644
--- a/src/test/ui/issues/issue-20605.stderr
+++ b/src/test/ui/issues/issue-20605.stderr
@@ -4,8 +4,9 @@ error[E0277]: the size for values of type `dyn Iterator<Item = &'a mut u8>` cann
 LL |     for item in *things { *item = 0 }
    |                 ^^^^^^^ doesn't have a size known at compile-time
    |
-   = help: the trait `Sized` is not implemented for `dyn Iterator<Item = &'a mut u8>`
-   = note: required by `into_iter`
+   = help: the trait `std::marker::Sized` is not implemented for `dyn std::iter::Iterator<Item = &'a mut u8>`
+   = note: required because of the requirements on the impl of `std::iter::IntoIterator` for `dyn std::iter::Iterator<Item = &'a mut u8>`
+   = note: required by `std::iter::IntoIterator::into_iter`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/issues/issue-20831-debruijn.rs b/src/test/ui/issues/issue-20831-debruijn.rs
index d0e15cb393a..20d980763ea 100644
--- a/src/test/ui/issues/issue-20831-debruijn.rs
+++ b/src/test/ui/issues/issue-20831-debruijn.rs
@@ -28,9 +28,6 @@ impl<'a> Publisher<'a> for MyStruct<'a> {
     fn subscribe(&mut self, t : Box<dyn Subscriber<Input=<Self as Publisher>::Output> + 'a>) {
         // Not obvious, but there is an implicit lifetime here -------^
         //~^^ ERROR cannot infer
-        //~| ERROR cannot infer
-        //~| ERROR mismatched types
-        //~| ERROR mismatched types
         //
         // The fact that `Publisher` is using an implicit lifetime is
         // what was causing the debruijn accounting to be off, so
diff --git a/src/test/ui/issues/issue-20831-debruijn.stderr b/src/test/ui/issues/issue-20831-debruijn.stderr
index 1ab89e818e3..1764dd3cf67 100644
--- a/src/test/ui/issues/issue-20831-debruijn.stderr
+++ b/src/test/ui/issues/issue-20831-debruijn.stderr
@@ -1,88 +1,20 @@
-error[E0308]: mismatched types
-  --> $DIR/issue-20831-debruijn.rs:28:5
-   |
-LL | /     fn subscribe(&mut self, t : Box<dyn Subscriber<Input=<Self as Publisher>::Output> + 'a>) {
-LL | |         // Not obvious, but there is an implicit lifetime here -------^
-LL | |
-LL | |
-...  |
-LL | |         self.sub = t;
-LL | |     }
-   | |_____^ lifetime mismatch
-   |
-   = note: expected type `'a`
-              found type `'_`
-note: the anonymous lifetime #2 defined on the method body at 28:5...
-  --> $DIR/issue-20831-debruijn.rs:28:5
+error[E0495]: cannot infer an appropriate lifetime for lifetime parameter `'a` due to conflicting requirements
+  --> $DIR/issue-20831-debruijn.rs:28:33
    |
 LL |     fn subscribe(&mut self, t : Box<dyn Subscriber<Input=<Self as Publisher>::Output> + 'a>) {
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-note: ...does not necessarily outlive the lifetime `'a` as defined on the impl at 26:6
-  --> $DIR/issue-20831-debruijn.rs:26:6
+   |                                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
-LL | impl<'a> Publisher<'a> for MyStruct<'a> {
-   |      ^^
-
-error[E0308]: mismatched types
+note: first, the lifetime cannot outlive the anonymous lifetime #2 defined on the method body at 28:5...
   --> $DIR/issue-20831-debruijn.rs:28:5
    |
 LL | /     fn subscribe(&mut self, t : Box<dyn Subscriber<Input=<Self as Publisher>::Output> + 'a>) {
 LL | |         // Not obvious, but there is an implicit lifetime here -------^
 LL | |
-LL | |
+LL | |         //
 ...  |
 LL | |         self.sub = t;
 LL | |     }
-   | |_____^ lifetime mismatch
-   |
-   = note: expected type `'a`
-              found type `'_`
-note: the lifetime `'a` as defined on the impl at 26:6...
-  --> $DIR/issue-20831-debruijn.rs:26:6
-   |
-LL | impl<'a> Publisher<'a> for MyStruct<'a> {
-   |      ^^
-note: ...does not necessarily outlive the anonymous lifetime #2 defined on the method body at 28:5
-  --> $DIR/issue-20831-debruijn.rs:28:5
-   |
-LL |     fn subscribe(&mut self, t : Box<dyn Subscriber<Input=<Self as Publisher>::Output> + 'a>) {
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
-error[E0495]: cannot infer an appropriate lifetime for lifetime parameter `'a` due to conflicting requirements
-  --> $DIR/issue-20831-debruijn.rs:28:33
-   |
-LL |     fn subscribe(&mut self, t : Box<dyn Subscriber<Input=<Self as Publisher>::Output> + 'a>) {
-   |                                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-note: first, the lifetime cannot outlive the anonymous lifetime #2 defined on the method body at 28:5...
-  --> $DIR/issue-20831-debruijn.rs:28:5
-   |
-LL |     fn subscribe(&mut self, t : Box<dyn Subscriber<Input=<Self as Publisher>::Output> + 'a>) {
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-note: ...but the lifetime must also be valid for the lifetime `'a` as defined on the impl at 26:6...
-  --> $DIR/issue-20831-debruijn.rs:26:6
-   |
-LL | impl<'a> Publisher<'a> for MyStruct<'a> {
-   |      ^^
-note: ...so that the types are compatible
-  --> $DIR/issue-20831-debruijn.rs:28:33
-   |
-LL |     fn subscribe(&mut self, t : Box<dyn Subscriber<Input=<Self as Publisher>::Output> + 'a>) {
-   |                                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   = note: expected `Publisher<'_>`
-              found `Publisher<'_>`
-
-error[E0495]: cannot infer an appropriate lifetime for lifetime parameter `'a` due to conflicting requirements
-  --> $DIR/issue-20831-debruijn.rs:28:33
-   |
-LL |     fn subscribe(&mut self, t : Box<dyn Subscriber<Input=<Self as Publisher>::Output> + 'a>) {
-   |                                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-note: first, the lifetime cannot outlive the anonymous lifetime #2 defined on the method body at 28:5...
-  --> $DIR/issue-20831-debruijn.rs:28:5
-   |
-LL |     fn subscribe(&mut self, t : Box<dyn Subscriber<Input=<Self as Publisher>::Output> + 'a>) {
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   | |_____^
 note: ...but the lifetime must also be valid for the lifetime `'a` as defined on the impl at 26:6...
   --> $DIR/issue-20831-debruijn.rs:26:6
    |
@@ -96,7 +28,6 @@ LL |     fn subscribe(&mut self, t : Box<dyn Subscriber<Input=<Self as Publisher
    = note: expected `Publisher<'_>`
               found `Publisher<'_>`
 
-error: aborting due to 4 previous errors
+error: aborting due to previous error
 
-Some errors have detailed explanations: E0308, E0495.
-For more information about an error, try `rustc --explain E0308`.
+For more information about this error, try `rustc --explain E0495`.
diff --git a/src/test/ui/issues/issue-21946.rs b/src/test/ui/issues/issue-21946.rs
index 0a9f8f50bdc..d0c052cb2fd 100644
--- a/src/test/ui/issues/issue-21946.rs
+++ b/src/test/ui/issues/issue-21946.rs
@@ -5,7 +5,6 @@ trait Foo {
 struct FooStruct;
 
 impl Foo for FooStruct {
-    //~^ ERROR overflow evaluating the requirement `<FooStruct as Foo>::A == _`
     type A = <FooStruct as Foo>::A;
     //~^ ERROR overflow evaluating the requirement `<FooStruct as Foo>::A == _`
 }
diff --git a/src/test/ui/issues/issue-21946.stderr b/src/test/ui/issues/issue-21946.stderr
index 582ce393d7f..8b96e0f3382 100644
--- a/src/test/ui/issues/issue-21946.stderr
+++ b/src/test/ui/issues/issue-21946.stderr
@@ -1,15 +1,9 @@
-error[E0275]: overflow evaluating the requirement `<FooStruct as Foo>::A == _`
-  --> $DIR/issue-21946.rs:7:6
-   |
-LL | impl Foo for FooStruct {
-   |      ^^^
-
-error[E0275]: overflow evaluating the requirement `<FooStruct as Foo>::A == _`
-  --> $DIR/issue-21946.rs:9:5
+error[E0275]: overflow evaluating the requirement `<FooStruct as Foo>::A`
+  --> $DIR/issue-21946.rs:8:5
    |
 LL |     type A = <FooStruct as Foo>::A;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: aborting due to 2 previous errors
+error: aborting due to previous error
 
 For more information about this error, try `rustc --explain E0275`.
diff --git a/src/test/ui/issues/issue-23122-1.rs b/src/test/ui/issues/issue-23122-1.rs
index d6f64650f36..0937e029ef4 100644
--- a/src/test/ui/issues/issue-23122-1.rs
+++ b/src/test/ui/issues/issue-23122-1.rs
@@ -5,7 +5,6 @@ trait Next {
 struct GetNext<T: Next> { t: T }
 
 impl<T: Next> Next for GetNext<T> {
-    //~^ ERROR overflow evaluating the requirement
     type Next = <GetNext<T> as Next>::Next;
     //~^ ERROR overflow evaluating the requirement
 }
diff --git a/src/test/ui/issues/issue-23122-1.stderr b/src/test/ui/issues/issue-23122-1.stderr
index 4e2e837c07c..f8374905370 100644
--- a/src/test/ui/issues/issue-23122-1.stderr
+++ b/src/test/ui/issues/issue-23122-1.stderr
@@ -1,15 +1,9 @@
-error[E0275]: overflow evaluating the requirement `<GetNext<T> as Next>::Next == _`
-  --> $DIR/issue-23122-1.rs:7:15
-   |
-LL | impl<T: Next> Next for GetNext<T> {
-   |               ^^^^
-
-error[E0275]: overflow evaluating the requirement `<GetNext<T> as Next>::Next == _`
-  --> $DIR/issue-23122-1.rs:9:5
+error[E0275]: overflow evaluating the requirement `<GetNext<T> as Next>::Next`
+  --> $DIR/issue-23122-1.rs:8:5
    |
 LL |     type Next = <GetNext<T> as Next>::Next;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: aborting due to 2 previous errors
+error: aborting due to previous error
 
 For more information about this error, try `rustc --explain E0275`.
diff --git a/src/test/ui/issues/issue-23122-2.rs b/src/test/ui/issues/issue-23122-2.rs
index 695712d2cc9..84abebf6b74 100644
--- a/src/test/ui/issues/issue-23122-2.rs
+++ b/src/test/ui/issues/issue-23122-2.rs
@@ -5,7 +5,6 @@ trait Next {
 struct GetNext<T: Next> { t: T }
 
 impl<T: Next> Next for GetNext<T> {
-    //~^ ERROR overflow evaluating the requirement
     type Next = <GetNext<T::Next> as Next>::Next;
     //~^ ERROR overflow evaluating the requirement
 }
diff --git a/src/test/ui/issues/issue-23122-2.stderr b/src/test/ui/issues/issue-23122-2.stderr
index 60dbb15d0f9..0d645bbcea5 100644
--- a/src/test/ui/issues/issue-23122-2.stderr
+++ b/src/test/ui/issues/issue-23122-2.stderr
@@ -1,14 +1,5 @@
-error[E0275]: overflow evaluating the requirement `<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<T as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next: Sized`
-  --> $DIR/issue-23122-2.rs:7:15
-   |
-LL | impl<T: Next> Next for GetNext<T> {
-   |               ^^^^
-   |
-   = help: consider adding a `#![recursion_limit="256"]` attribute to your crate (`issue_23122_2`)
-   = note: required because of the requirements on the impl of `Next` for `GetNext<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<T as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next>`
-
-error[E0275]: overflow evaluating the requirement `<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<T as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next: Sized`
-  --> $DIR/issue-23122-2.rs:9:5
+error[E0275]: overflow evaluating the requirement `<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<T as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next: std::marker::Sized`
+  --> $DIR/issue-23122-2.rs:8:5
    |
 LL |     type Next = <GetNext<T::Next> as Next>::Next;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -16,6 +7,6 @@ LL |     type Next = <GetNext<T::Next> as Next>::Next;
    = help: consider adding a `#![recursion_limit="256"]` attribute to your crate (`issue_23122_2`)
    = note: required because of the requirements on the impl of `Next` for `GetNext<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<T as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next as Next>::Next>`
 
-error: aborting due to 2 previous errors
+error: aborting due to previous error
 
 For more information about this error, try `rustc --explain E0275`.
diff --git a/src/test/ui/issues/issue-24204.rs b/src/test/ui/issues/issue-24204.rs
index 61671b32e9b..df72283de23 100644
--- a/src/test/ui/issues/issue-24204.rs
+++ b/src/test/ui/issues/issue-24204.rs
@@ -12,6 +12,6 @@ trait Trait: Sized {
 }
 
 fn test<T: Trait<B=i32>>(b: i32) -> T where T::A: MultiDispatch<i32> { T::new(b) }
-//~^ ERROR type mismatch resolving
+//~^ ERROR mismatched types
 
 fn main() {}
diff --git a/src/test/ui/issues/issue-24204.stderr b/src/test/ui/issues/issue-24204.stderr
index d5cbcf786bf..9d66c9ff0a8 100644
--- a/src/test/ui/issues/issue-24204.stderr
+++ b/src/test/ui/issues/issue-24204.stderr
@@ -1,15 +1,10 @@
-error[E0271]: type mismatch resolving `<<T as Trait>::A as MultiDispatch<i32>>::O == T`
-  --> $DIR/issue-24204.rs:14:12
+error[E0308]: mismatched types
+  --> $DIR/issue-24204.rs:14:72
    |
-LL | trait Trait: Sized {
-   |       ----- required by a bound in this
-LL |     type A: MultiDispatch<Self::B, O = Self>;
-   |                                    -------- required by this bound in `Trait`
-...
 LL | fn test<T: Trait<B=i32>>(b: i32) -> T where T::A: MultiDispatch<i32> { T::new(b) }
-   |         -  ^^^^^^^^^^^^ expected type parameter `T`, found associated type
-   |         |
-   |         this type parameter
+   |         -                           -                                  ^^^^^^^^^ expected type parameter `T`, found associated type
+   |         |                           |
+   |         this type parameter         expected `T` because of return type
    |
    = note: expected type parameter `T`
              found associated type `<<T as Trait>::A as MultiDispatch<i32>>::O`
@@ -17,4 +12,4 @@ LL | fn test<T: Trait<B=i32>>(b: i32) -> T where T::A: MultiDispatch<i32> { T::n
 
 error: aborting due to previous error
 
-For more information about this error, try `rustc --explain E0271`.
+For more information about this error, try `rustc --explain E0308`.
diff --git a/src/test/ui/issues/issue-28098.stderr b/src/test/ui/issues/issue-28098.stderr
index df552fc2d0e..04075911111 100644
--- a/src/test/ui/issues/issue-28098.stderr
+++ b/src/test/ui/issues/issue-28098.stderr
@@ -13,8 +13,9 @@ error[E0277]: `bool` is not an iterator
 LL |     for _ in false {}
    |              ^^^^^ `bool` is not an iterator
    |
-   = help: the trait `Iterator` is not implemented for `bool`
-   = note: required by `into_iter`
+   = help: the trait `std::iter::Iterator` is not implemented for `bool`
+   = note: required because of the requirements on the impl of `std::iter::IntoIterator` for `bool`
+   = note: required by `std::iter::IntoIterator::into_iter`
 
 error[E0277]: `()` is not an iterator
   --> $DIR/issue-28098.rs:9:28
diff --git a/src/test/ui/issues/issue-33941.stderr b/src/test/ui/issues/issue-33941.stderr
index aeab923d2df..81d97bdbf12 100644
--- a/src/test/ui/issues/issue-33941.stderr
+++ b/src/test/ui/issues/issue-33941.stderr
@@ -15,7 +15,9 @@ LL |     for _ in HashMap::new().iter().cloned() {}
    |
    = note:  expected tuple `(&_, &_)`
            found reference `&_`
-   = note: required because of the requirements on the impl of `Iterator` for `Cloned<std::collections::hash_map::Iter<'_, _, _>>`
+   = note: required because of the requirements on the impl of `std::iter::Iterator` for `std::iter::Cloned<std::collections::hash_map::Iter<'_, _, _>>`
+   = note: required because of the requirements on the impl of `std::iter::IntoIterator` for `std::iter::Cloned<std::collections::hash_map::Iter<'_, _, _>>`
+   = note: required by `std::iter::IntoIterator::into_iter`
 
 error[E0271]: type mismatch resolving `<std::collections::hash_map::Iter<'_, _, _> as Iterator>::Item == &_`
   --> $DIR/issue-33941.rs:4:14
diff --git a/src/test/ui/issues/issue-38091.stderr b/src/test/ui/issues/issue-38091.stderr
index 81beec80263..f47fd8d1b0d 100644
--- a/src/test/ui/issues/issue-38091.stderr
+++ b/src/test/ui/issues/issue-38091.stderr
@@ -11,7 +11,7 @@ error[E0277]: the trait bound `(): Valid` is not satisfied
   --> $DIR/issue-38091.rs:9:5
    |
 LL |     type Ty: Valid;
-   |     --------------- required by `Iterate::Ty`
+   |              ----- required by this bound in `Iterate::Ty`
 ...
 LL |     default type Ty = ();
    |     ^^^^^^^^^^^^^^^^^^^^^ the trait `Valid` is not implemented for `()`
diff --git a/src/test/ui/issues/issue-43784-associated-type.stderr b/src/test/ui/issues/issue-43784-associated-type.stderr
index 039852ad165..7b656ef8559 100644
--- a/src/test/ui/issues/issue-43784-associated-type.stderr
+++ b/src/test/ui/issues/issue-43784-associated-type.stderr
@@ -1,8 +1,11 @@
-error[E0277]: the trait bound `T: Copy` is not satisfied
-  --> $DIR/issue-43784-associated-type.rs:14:18
+error[E0277]: the trait bound `T: std::marker::Copy` is not satisfied
+  --> $DIR/issue-43784-associated-type.rs:14:5
    |
+LL |     type Assoc: Partial<Self>;
+   |                 ------------- required by this bound in `Complete::Assoc`
+...
 LL |     type Assoc = T;
-   |                  ^ the trait `Copy` is not implemented for `T`
+   |     ^^^^^^^^^^^^^^^ the trait `std::marker::Copy` is not implemented for `T`
    |
 help: consider restricting type parameter `T`
    |
diff --git a/src/test/ui/issues/issue-43784-supertrait.stderr b/src/test/ui/issues/issue-43784-supertrait.stderr
index d92e4fa9e4a..c73536ba973 100644
--- a/src/test/ui/issues/issue-43784-supertrait.stderr
+++ b/src/test/ui/issues/issue-43784-supertrait.stderr
@@ -1,6 +1,9 @@
 error[E0277]: the trait bound `T: Copy` is not satisfied
   --> $DIR/issue-43784-supertrait.rs:8:9
    |
+LL | pub trait Complete: Partial {
+   |                     ------- required by this bound in `Complete`
+...
 LL | impl<T> Complete for T {}
    |         ^^^^^^^^ the trait `Copy` is not implemented for `T`
    |
diff --git a/src/test/ui/issues/issue-65673.stderr b/src/test/ui/issues/issue-65673.stderr
index aa43ac9414f..64cc0bab3f3 100644
--- a/src/test/ui/issues/issue-65673.stderr
+++ b/src/test/ui/issues/issue-65673.stderr
@@ -1,13 +1,11 @@
 error[E0277]: the size for values of type `(dyn Trait + 'static)` cannot be known at compilation time
-  --> $DIR/issue-65673.rs:9:16
+  --> $DIR/issue-65673.rs:9:5
    |
-LL | trait WithType {
-   |       -------- required by a bound in this
 LL |     type Ctx;
-   |     --------- required by this bound in `WithType`
+   |     --------- required by this bound in `WithType::Ctx`
 ...
 LL |     type Ctx = dyn Alias<T>;
-   |                ^^^^^^^^^^^^ doesn't have a size known at compile-time
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
    |
    = help: the trait `Sized` is not implemented for `(dyn Trait + 'static)`
 
diff --git a/src/test/ui/never_type/issue-51506.stderr b/src/test/ui/never_type/issue-51506.stderr
index c54cbe9b4d1..16d93c18900 100644
--- a/src/test/ui/never_type/issue-51506.stderr
+++ b/src/test/ui/never_type/issue-51506.stderr
@@ -2,7 +2,7 @@ error[E0277]: `!` is not an iterator
   --> $DIR/issue-51506.rs:13:5
    |
 LL |     type Out: Iterator<Item = u32>;
-   |     ------------------------------- required by `Trait::Out`
+   |               -------------------- required by this bound in `Trait::Out`
 ...
 LL |     default type Out = !;
    |     ^^^^^^^^^^^^^^^^^^^^^ `!` is not an iterator
diff --git a/src/test/ui/nll/relate_tys/impl-fn-ignore-binder-via-bottom.rs b/src/test/ui/nll/relate_tys/impl-fn-ignore-binder-via-bottom.rs
index d3964a7f515..44dcd191d1b 100644
--- a/src/test/ui/nll/relate_tys/impl-fn-ignore-binder-via-bottom.rs
+++ b/src/test/ui/nll/relate_tys/impl-fn-ignore-binder-via-bottom.rs
@@ -32,5 +32,4 @@ fn main() {
     let _x = <fn(&())>::make_f();
     //~^ higher-ranked subtype error
     //~| higher-ranked subtype error
-    //~| higher-ranked subtype error
 }
diff --git a/src/test/ui/nll/relate_tys/impl-fn-ignore-binder-via-bottom.stderr b/src/test/ui/nll/relate_tys/impl-fn-ignore-binder-via-bottom.stderr
index 70fb877d716..190b520c678 100644
--- a/src/test/ui/nll/relate_tys/impl-fn-ignore-binder-via-bottom.stderr
+++ b/src/test/ui/nll/relate_tys/impl-fn-ignore-binder-via-bottom.stderr
@@ -10,11 +10,5 @@ error: higher-ranked subtype error
 LL |     let _x = <fn(&())>::make_f();
    |              ^^^^^^^^^^^^^^^^^^^
 
-error: higher-ranked subtype error
-  --> $DIR/impl-fn-ignore-binder-via-bottom.rs:32:14
-   |
-LL |     let _x = <fn(&())>::make_f();
-   |              ^^^^^^^^^^^^^^^^^^^
-
-error: aborting due to 3 previous errors
+error: aborting due to 2 previous errors
 
diff --git a/src/test/ui/privacy/private-in-public-assoc-ty.rs b/src/test/ui/privacy/private-in-public-assoc-ty.rs
index 5238894a974..fdf0bc38391 100644
--- a/src/test/ui/privacy/private-in-public-assoc-ty.rs
+++ b/src/test/ui/privacy/private-in-public-assoc-ty.rs
@@ -29,7 +29,11 @@ mod m {
         //~| WARN this was previously accepted
         type Alias1: PrivTr;
         type Alias2: PubTrAux1<Priv> = u8;
+        //~^ WARN private type `m::Priv` in public interface
+        //~| WARN this was previously accepted
         type Alias3: PubTrAux2<A = Priv> = u8;
+        //~^ WARN private type `m::Priv` in public interface
+        //~| WARN this was previously accepted
 
         type Alias4 = Priv;
         //~^ ERROR private type `Priv` in public interface
diff --git a/src/test/ui/privacy/private-in-public-assoc-ty.stderr b/src/test/ui/privacy/private-in-public-assoc-ty.stderr
index acc6e20cf33..768dca17e07 100644
--- a/src/test/ui/privacy/private-in-public-assoc-ty.stderr
+++ b/src/test/ui/privacy/private-in-public-assoc-ty.stderr
@@ -10,14 +10,8 @@ LL |         type A = Priv;
 warning: private trait `PrivTr` in public interface (error E0445)
   --> $DIR/private-in-public-assoc-ty.rs:23:5
    |
-LL | /     pub trait PubTr {
-LL | |
-LL | |
-LL | |
-...  |
-LL | |         fn infer_exist() -> Self::Exist;
-LL | |     }
-   | |_____^
+LL |         type Alias1: PrivTr;
+   |         ^^^^^^^^^^^^^^^^^^^^
    |
    = note: `#[warn(private_in_public)]` on by default
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
@@ -26,14 +20,8 @@ LL | |     }
 warning: private type `Priv` in public interface (error E0446)
   --> $DIR/private-in-public-assoc-ty.rs:23:5
    |
-LL | /     pub trait PubTr {
-LL | |
-LL | |
-LL | |
-...  |
-LL | |         fn infer_exist() -> Self::Exist;
-LL | |     }
-   | |_____^
+LL |         type Alias2: PubTrAux1<Priv> = u8;
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
    = note: for more information, see issue #34537 <https://github.com/rust-lang/rust/issues/34537>
@@ -41,14 +29,8 @@ LL | |     }
 warning: private type `Priv` in public interface (error E0446)
   --> $DIR/private-in-public-assoc-ty.rs:23:5
    |
-LL | /     pub trait PubTr {
-LL | |
-LL | |
-LL | |
-...  |
-LL | |         fn infer_exist() -> Self::Exist;
-LL | |     }
-   | |_____^
+LL |         type Alias3: PubTrAux2<A = Priv> = u8;
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
    = note: for more information, see issue #34537 <https://github.com/rust-lang/rust/issues/34537>
diff --git a/src/test/ui/privacy/private-in-public-warn.rs b/src/test/ui/privacy/private-in-public-warn.rs
index 3022b470b7d..1c8706d8ad2 100644
--- a/src/test/ui/privacy/private-in-public-warn.rs
+++ b/src/test/ui/privacy/private-in-public-warn.rs
@@ -55,9 +55,9 @@ mod traits {
     pub trait Tr2<T: PrivTr> {} //~ ERROR private trait `traits::PrivTr` in public interface
         //~^ WARNING hard error
     pub trait Tr3 {
+        type Alias: PrivTr;
         //~^ ERROR private trait `traits::PrivTr` in public interface
         //~| WARNING hard error
-        type Alias: PrivTr;
         fn f<T: PrivTr>(arg: T) {} //~ ERROR private trait `traits::PrivTr` in public interface
         //~^ WARNING hard error
     }
diff --git a/src/test/ui/privacy/private-in-public-warn.stderr b/src/test/ui/privacy/private-in-public-warn.stderr
index 36577a60102..f50dc48f8ad 100644
--- a/src/test/ui/privacy/private-in-public-warn.stderr
+++ b/src/test/ui/privacy/private-in-public-warn.stderr
@@ -130,16 +130,10 @@ LL |     pub trait Tr2<T: PrivTr> {}
    = note: for more information, see issue #34537 <https://github.com/rust-lang/rust/issues/34537>
 
 error: private trait `traits::PrivTr` in public interface (error E0445)
-  --> $DIR/private-in-public-warn.rs:57:5
-   |
-LL | /     pub trait Tr3 {
-LL | |
-LL | |
-LL | |         type Alias: PrivTr;
-LL | |         fn f<T: PrivTr>(arg: T) {}
-LL | |
-LL | |     }
-   | |_____^
+  --> $DIR/private-in-public-warn.rs:58:9
+   |
+LL |         type Alias: PrivTr;
+   |         ^^^^^^^^^^^^^^^^^^^
    |
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
    = note: for more information, see issue #34537 <https://github.com/rust-lang/rust/issues/34537>
diff --git a/src/test/ui/privacy/pub-priv-dep/pub-priv1.rs b/src/test/ui/privacy/pub-priv-dep/pub-priv1.rs
index e485263affc..5476e35b5f6 100644
--- a/src/test/ui/privacy/pub-priv-dep/pub-priv1.rs
+++ b/src/test/ui/privacy/pub-priv-dep/pub-priv1.rs
@@ -1,5 +1,5 @@
- // aux-crate:priv:priv_dep=priv_dep.rs
- // aux-build:pub_dep.rs
+// aux-crate:priv:priv_dep=priv_dep.rs
+// aux-build:pub_dep.rs
 #![deny(exported_private_dependencies)]
 
 // This crate is a private dependency
@@ -7,20 +7,20 @@ extern crate priv_dep;
 // This crate is a public dependency
 extern crate pub_dep;
 
-use priv_dep::{OtherType, OtherTrait};
+use priv_dep::{OtherTrait, OtherType};
 use pub_dep::PubType;
 
 // Type from private dependency used in private
 // type - this is fine
 struct PrivateType {
-    field: OtherType
+    field: OtherType,
 }
 
 pub struct PublicType {
     pub field: OtherType,
     //~^ ERROR type `OtherType` from private dependency 'priv_dep' in public interface
-    priv_field: OtherType, // Private field - this is fine
-    pub other_field: PubType // Type from public dependency - this is fine
+    priv_field: OtherType,    // Private field - this is fine
+    pub other_field: PubType, // Type from public dependency - this is fine
 }
 
 impl PublicType {
@@ -32,14 +32,13 @@ impl PublicType {
 
 pub trait MyPubTrait {
     type Foo: OtherTrait;
+    //~^ ERROR trait `priv_dep::OtherTrait` from private dependency 'priv_dep' in public interface
 }
 //~^^^ ERROR trait `OtherTrait` from private dependency 'priv_dep' in public interface
 
 pub struct AllowedPrivType {
     #[allow(exported_private_dependencies)]
-    pub allowed: OtherType
+    pub allowed: OtherType,
 }
 
-
-
 fn main() {}
diff --git a/src/test/ui/privacy/pub-priv-dep/pub-priv1.stderr b/src/test/ui/privacy/pub-priv-dep/pub-priv1.stderr
index 3b5b7823443..e6fd6fc7bb8 100644
--- a/src/test/ui/privacy/pub-priv-dep/pub-priv1.stderr
+++ b/src/test/ui/privacy/pub-priv-dep/pub-priv1.stderr
@@ -19,10 +19,8 @@ LL |     pub fn pub_fn(param: OtherType) {}
 error: trait `OtherTrait` from private dependency 'priv_dep' in public interface
   --> $DIR/pub-priv1.rs:33:1
    |
-LL | / pub trait MyPubTrait {
-LL | |     type Foo: OtherTrait;
-LL | | }
-   | |_^
+LL |     type Foo: OtherTrait;
+   |     ^^^^^^^^^^^^^^^^^^^^^
 
 error: aborting due to 3 previous errors
 
diff --git a/src/test/ui/question-mark-type-infer.stderr b/src/test/ui/question-mark-type-infer.stderr
index f530534ec80..a896d587533 100644
--- a/src/test/ui/question-mark-type-infer.stderr
+++ b/src/test/ui/question-mark-type-infer.stderr
@@ -1,4 +1,4 @@
-error[E0284]: type annotations needed
+error[E0283]: type annotations needed
   --> $DIR/question-mark-type-infer.rs:12:21
    |
 LL |     l.iter().map(f).collect()?
@@ -12,4 +12,4 @@ LL |     l.iter().map(f).collect::<B>()?
 
 error: aborting due to previous error
 
-For more information about this error, try `rustc --explain E0284`.
+For more information about this error, try `rustc --explain E0283`.
diff --git a/src/test/ui/range/range-1.stderr b/src/test/ui/range/range-1.stderr
index a7557320faa..e380e5b2f91 100644
--- a/src/test/ui/range/range-1.stderr
+++ b/src/test/ui/range/range-1.stderr
@@ -17,7 +17,7 @@ error[E0277]: the size for values of type `[{integer}]` cannot be known at compi
    |
 LL |     let range = *arr..;
    |                 ^^^^^^ doesn't have a size known at compile-time
-   | 
+   |
   ::: $SRC_DIR/core/src/ops/range.rs:LL:COL
    |
 LL | pub struct RangeFrom<Idx> {
diff --git a/src/test/ui/regions/regions-assoc-type-region-bound-in-trait-not-met.rs b/src/test/ui/regions/regions-assoc-type-region-bound-in-trait-not-met.rs
index 26cb40bb5c2..0f86e37b7e5 100644
--- a/src/test/ui/regions/regions-assoc-type-region-bound-in-trait-not-met.rs
+++ b/src/test/ui/regions/regions-assoc-type-region-bound-in-trait-not-met.rs
@@ -12,13 +12,13 @@ impl<'a> Foo<'a> for &'a i16 {
 }
 
 impl<'a> Foo<'static> for &'a i32 {
-    //~^ ERROR cannot infer
     type Value = &'a i32;
+    //~^ ERROR lifetime bound not satisfied
 }
 
 impl<'a,'b> Foo<'b> for &'a i64 {
-    //~^ ERROR cannot infer
     type Value = &'a i32;
+    //~^ ERROR lifetime bound not satisfied
 }
 
 fn main() { }
diff --git a/src/test/ui/regions/regions-assoc-type-region-bound-in-trait-not-met.stderr b/src/test/ui/regions/regions-assoc-type-region-bound-in-trait-not-met.stderr
index c134b3b3ed5..feb9c90bc8f 100644
--- a/src/test/ui/regions/regions-assoc-type-region-bound-in-trait-not-met.stderr
+++ b/src/test/ui/regions/regions-assoc-type-region-bound-in-trait-not-met.stderr
@@ -1,57 +1,33 @@
-error[E0495]: cannot infer an appropriate lifetime for lifetime parameter `'a` due to conflicting requirements
-  --> $DIR/regions-assoc-type-region-bound-in-trait-not-met.rs:14:10
+error[E0478]: lifetime bound not satisfied
+  --> $DIR/regions-assoc-type-region-bound-in-trait-not-met.rs:15:5
    |
-LL | impl<'a> Foo<'static> for &'a i32 {
-   |          ^^^^^^^^^^^^
+LL |     type Value = &'a i32;
+   |     ^^^^^^^^^^^^^^^^^^^^^
    |
-note: first, the lifetime cannot outlive the lifetime `'a` as defined on the impl at 14:6...
+note: lifetime parameter instantiated with the lifetime `'a` as defined on the impl at 14:6
   --> $DIR/regions-assoc-type-region-bound-in-trait-not-met.rs:14:6
    |
 LL | impl<'a> Foo<'static> for &'a i32 {
    |      ^^
-note: ...so that the types are compatible
-  --> $DIR/regions-assoc-type-region-bound-in-trait-not-met.rs:14:10
-   |
-LL | impl<'a> Foo<'static> for &'a i32 {
-   |          ^^^^^^^^^^^^
-   = note: expected `Foo<'static>`
-              found `Foo<'static>`
-   = note: but, the lifetime must be valid for the static lifetime...
-note: ...so that the type `&i32` will meet its required lifetime bounds
-  --> $DIR/regions-assoc-type-region-bound-in-trait-not-met.rs:14:10
-   |
-LL | impl<'a> Foo<'static> for &'a i32 {
-   |          ^^^^^^^^^^^^
+   = note: but lifetime parameter must outlive the static lifetime
 
-error[E0495]: cannot infer an appropriate lifetime for lifetime parameter `'a` due to conflicting requirements
-  --> $DIR/regions-assoc-type-region-bound-in-trait-not-met.rs:19:13
+error[E0478]: lifetime bound not satisfied
+  --> $DIR/regions-assoc-type-region-bound-in-trait-not-met.rs:20:5
    |
-LL | impl<'a,'b> Foo<'b> for &'a i64 {
-   |             ^^^^^^^
+LL |     type Value = &'a i32;
+   |     ^^^^^^^^^^^^^^^^^^^^^
    |
-note: first, the lifetime cannot outlive the lifetime `'a` as defined on the impl at 19:6...
+note: lifetime parameter instantiated with the lifetime `'a` as defined on the impl at 19:6
   --> $DIR/regions-assoc-type-region-bound-in-trait-not-met.rs:19:6
    |
 LL | impl<'a,'b> Foo<'b> for &'a i64 {
    |      ^^
-note: ...so that the types are compatible
-  --> $DIR/regions-assoc-type-region-bound-in-trait-not-met.rs:19:13
-   |
-LL | impl<'a,'b> Foo<'b> for &'a i64 {
-   |             ^^^^^^^
-   = note: expected `Foo<'b>`
-              found `Foo<'_>`
-note: but, the lifetime must be valid for the lifetime `'b` as defined on the impl at 19:9...
+note: but lifetime parameter must outlive the lifetime `'b` as defined on the impl at 19:9
   --> $DIR/regions-assoc-type-region-bound-in-trait-not-met.rs:19:9
    |
 LL | impl<'a,'b> Foo<'b> for &'a i64 {
    |         ^^
-note: ...so that the type `&i32` will meet its required lifetime bounds
-  --> $DIR/regions-assoc-type-region-bound-in-trait-not-met.rs:19:13
-   |
-LL | impl<'a,'b> Foo<'b> for &'a i64 {
-   |             ^^^^^^^
 
 error: aborting due to 2 previous errors
 
-For more information about this error, try `rustc --explain E0495`.
+For more information about this error, try `rustc --explain E0478`.
diff --git a/src/test/ui/regions/regions-assoc-type-static-bound-in-trait-not-met.rs b/src/test/ui/regions/regions-assoc-type-static-bound-in-trait-not-met.rs
index 599cd0bb756..65b54b45a0a 100644
--- a/src/test/ui/regions/regions-assoc-type-static-bound-in-trait-not-met.rs
+++ b/src/test/ui/regions/regions-assoc-type-static-bound-in-trait-not-met.rs
@@ -7,8 +7,8 @@ trait Foo {
 }
 
 impl<'a> Foo for &'a i32 {
-    //~^ ERROR cannot infer
     type Value = &'a i32;
+    //~^ ERROR lifetime bound not satisfied
 }
 
 impl<'a> Foo for i32 {
diff --git a/src/test/ui/regions/regions-assoc-type-static-bound-in-trait-not-met.stderr b/src/test/ui/regions/regions-assoc-type-static-bound-in-trait-not-met.stderr
index ac8c55ccc8f..9b98d14a978 100644
--- a/src/test/ui/regions/regions-assoc-type-static-bound-in-trait-not-met.stderr
+++ b/src/test/ui/regions/regions-assoc-type-static-bound-in-trait-not-met.stderr
@@ -1,28 +1,16 @@
-error[E0495]: cannot infer an appropriate lifetime for lifetime parameter `'a` due to conflicting requirements
-  --> $DIR/regions-assoc-type-static-bound-in-trait-not-met.rs:9:10
+error[E0478]: lifetime bound not satisfied
+  --> $DIR/regions-assoc-type-static-bound-in-trait-not-met.rs:10:5
    |
-LL | impl<'a> Foo for &'a i32 {
-   |          ^^^
+LL |     type Value = &'a i32;
+   |     ^^^^^^^^^^^^^^^^^^^^^
    |
-note: first, the lifetime cannot outlive the lifetime `'a` as defined on the impl at 9:6...
+note: lifetime parameter instantiated with the lifetime `'a` as defined on the impl at 9:6
   --> $DIR/regions-assoc-type-static-bound-in-trait-not-met.rs:9:6
    |
 LL | impl<'a> Foo for &'a i32 {
    |      ^^
-note: ...so that the types are compatible
-  --> $DIR/regions-assoc-type-static-bound-in-trait-not-met.rs:9:10
-   |
-LL | impl<'a> Foo for &'a i32 {
-   |          ^^^
-   = note: expected `Foo`
-              found `Foo`
-   = note: but, the lifetime must be valid for the static lifetime...
-note: ...so that the type `&i32` will meet its required lifetime bounds
-  --> $DIR/regions-assoc-type-static-bound-in-trait-not-met.rs:9:10
-   |
-LL | impl<'a> Foo for &'a i32 {
-   |          ^^^
+   = note: but lifetime parameter must outlive the static lifetime
 
 error: aborting due to previous error
 
-For more information about this error, try `rustc --explain E0495`.
+For more information about this error, try `rustc --explain E0478`.
diff --git a/src/test/ui/specialization/deafult-associated-type-bound-1.stderr b/src/test/ui/specialization/deafult-associated-type-bound-1.stderr
index 612e22c204f..4c21f8db8fa 100644
--- a/src/test/ui/specialization/deafult-associated-type-bound-1.stderr
+++ b/src/test/ui/specialization/deafult-associated-type-bound-1.stderr
@@ -11,7 +11,7 @@ error[E0277]: the trait bound `str: Clone` is not satisfied
   --> $DIR/deafult-associated-type-bound-1.rs:18:5
    |
 LL |     type U: Clone;
-   |     -------------- required by `X::U`
+   |             ----- required by this bound in `X::U`
 ...
 LL |     default type U = str;
    |     ^^^^^^^^^^^^^^^^^^^^^ the trait `Clone` is not implemented for `str`
diff --git a/src/test/ui/specialization/deafult-associated-type-bound-2.stderr b/src/test/ui/specialization/deafult-associated-type-bound-2.stderr
index a14024c160f..8c9da81d277 100644
--- a/src/test/ui/specialization/deafult-associated-type-bound-2.stderr
+++ b/src/test/ui/specialization/deafult-associated-type-bound-2.stderr
@@ -11,7 +11,7 @@ error[E0277]: can't compare `&'static B` with `B`
   --> $DIR/deafult-associated-type-bound-2.rs:16:5
    |
 LL |     type U: PartialEq<T>;
-   |     --------------------- required by `X::U`
+   |             ------------ required by this bound in `X::U`
 ...
 LL |     default type U = &'static B;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ no implementation for `&'static B == B`
diff --git a/src/test/ui/specialization/deafult-generic-associated-type-bound.rs b/src/test/ui/specialization/deafult-generic-associated-type-bound.rs
index 8a94ea658d2..f14588e6e02 100644
--- a/src/test/ui/specialization/deafult-generic-associated-type-bound.rs
+++ b/src/test/ui/specialization/deafult-generic-associated-type-bound.rs
@@ -6,7 +6,7 @@
 //~^^ WARNING the feature `generic_associated_types` is incomplete
 
 trait X {
-    type U<'a>: PartialEq<&'a Self>;
+    type U<'a>: PartialEq<&'a Self> where Self: 'a;
     fn unsafe_compare<'b>(x: Option<Self::U<'b>>, y: Option<&'b Self>) {
         match (x, y) {
             (Some(a), Some(b)) => a == b,
diff --git a/src/test/ui/specialization/deafult-generic-associated-type-bound.stderr b/src/test/ui/specialization/deafult-generic-associated-type-bound.stderr
index 556feda642b..f145b90f216 100644
--- a/src/test/ui/specialization/deafult-generic-associated-type-bound.stderr
+++ b/src/test/ui/specialization/deafult-generic-associated-type-bound.stderr
@@ -18,8 +18,8 @@ LL | #![feature(generic_associated_types)]
 error[E0277]: can't compare `T` with `T`
   --> $DIR/deafult-generic-associated-type-bound.rs:19:5
    |
-LL |     type U<'a>: PartialEq<&'a Self>;
-   |     -------------------------------- required by `X::U`
+LL |     type U<'a>: PartialEq<&'a Self> where Self: 'a;
+   |                 ------------------- required by this bound in `X::U`
 ...
 LL |     default type U<'a> = &'a T;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^ no implementation for `T == T`
diff --git a/src/test/ui/specialization/issue-44861.stderr b/src/test/ui/specialization/issue-44861.stderr
index be7196a63ce..3935a4a5f99 100644
--- a/src/test/ui/specialization/issue-44861.stderr
+++ b/src/test/ui/specialization/issue-44861.stderr
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `(): CoerceUnsized<*const [u8]>` is not satisfied
   --> $DIR/issue-44861.rs:21:5
    |
 LL |     type Data2: CoerceUnsized<*const [u8]>;
-   |     --------------------------------------- required by `Smartass::Data2`
+   |                 -------------------------- required by this bound in `Smartass::Data2`
 ...
 LL |     default type Data2 = ();
    |     ^^^^^^^^^^^^^^^^^^^^^^^^ the trait `CoerceUnsized<*const [u8]>` is not implemented for `()`
diff --git a/src/test/ui/specialization/issue-59435.stderr b/src/test/ui/specialization/issue-59435.stderr
index ee5c0615927..f3f8b022b01 100644
--- a/src/test/ui/specialization/issue-59435.stderr
+++ b/src/test/ui/specialization/issue-59435.stderr
@@ -2,7 +2,7 @@ error[E0277]: the trait bound `MyStruct: Default` is not satisfied
   --> $DIR/issue-59435.rs:11:5
    |
 LL |     type MyType: Default;
-   |     --------------------- required by `MyTrait::MyType`
+   |                  ------- required by this bound in `MyTrait::MyType`
 ...
 LL |     default type MyType = MyStruct;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Default` is not implemented for `MyStruct`
diff --git a/src/test/ui/suggestions/missing-assoc-type-bound-restriction.rs b/src/test/ui/suggestions/missing-assoc-type-bound-restriction.rs
index 394512c5794..8218fecc3f1 100644
--- a/src/test/ui/suggestions/missing-assoc-type-bound-restriction.rs
+++ b/src/test/ui/suggestions/missing-assoc-type-bound-restriction.rs
@@ -15,11 +15,9 @@ impl<A, T> Child<A> for ChildWrapper<T> where T: Child<A> {}
 struct ParentWrapper<T>(T);
 
 impl<A, T: Parent<Ty = A>> Parent for ParentWrapper<T> {
-    //~^ ERROR the trait bound `<T as Parent>::Assoc: Child<A>` is not satisfied
     type Ty = A;
     type Assoc = ChildWrapper<T::Assoc>;
     //~^ ERROR the trait bound `<T as Parent>::Assoc: Child<A>` is not satisfied
-    //~| ERROR the trait bound `<T as Parent>::Assoc: Child<A>` is not satisfied
 }
 
 fn main() {}
diff --git a/src/test/ui/suggestions/missing-assoc-type-bound-restriction.stderr b/src/test/ui/suggestions/missing-assoc-type-bound-restriction.stderr
index a8ea2147961..676e2fb1a51 100644
--- a/src/test/ui/suggestions/missing-assoc-type-bound-restriction.stderr
+++ b/src/test/ui/suggestions/missing-assoc-type-bound-restriction.stderr
@@ -1,55 +1,18 @@
 error[E0277]: the trait bound `<T as Parent>::Assoc: Child<A>` is not satisfied
-  --> $DIR/missing-assoc-type-bound-restriction.rs:17:19
+  --> $DIR/missing-assoc-type-bound-restriction.rs:19:5
    |
-LL | trait Parent {
-   |       ------ required by a bound in this
-LL |     type Ty;
 LL |     type Assoc: Child<Self::Ty>;
-   |                 --------------- required by this bound in `Parent`
-...
-LL | impl<A, T: Parent<Ty = A>> Parent for ParentWrapper<T> {
-   |                   ^^^^^^ the trait `Child<A>` is not implemented for `<T as Parent>::Assoc`
-   |
-help: consider further restricting the associated type
-   |
-LL | impl<A, T: Parent<Ty = A>> Parent for ParentWrapper<T> where <T as Parent>::Assoc: Child<A> {
-   |                                                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
-error[E0277]: the trait bound `<T as Parent>::Assoc: Child<A>` is not satisfied
-  --> $DIR/missing-assoc-type-bound-restriction.rs:20:18
-   |
-LL | trait Parent {
-   |       ------ required by a bound in this
-LL |     type Ty;
-LL |     type Assoc: Child<Self::Ty>;
-   |                 --------------- required by this bound in `Parent`
-...
-LL |     type Assoc = ChildWrapper<T::Assoc>;
-   |                  ^^^^^^^^^^^^^^^^^^^^^^ the trait `Child<A>` is not implemented for `<T as Parent>::Assoc`
-   |
-   = note: required because of the requirements on the impl of `Child<A>` for `ChildWrapper<<T as Parent>::Assoc>`
-help: consider further restricting the associated type
-   |
-LL | impl<A, T: Parent<Ty = A>> Parent for ParentWrapper<T> where <T as Parent>::Assoc: Child<A> {
-   |                                                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
-error[E0277]: the trait bound `<T as Parent>::Assoc: Child<A>` is not satisfied
-  --> $DIR/missing-assoc-type-bound-restriction.rs:20:5
-   |
-LL | trait Parent {
-   |       ------ required by a bound in this
-LL |     type Ty;
-LL |     type Assoc: Child<Self::Ty>;
-   |                 --------------- required by this bound in `Parent`
+   |                 --------------- required by this bound in `Parent::Assoc`
 ...
 LL |     type Assoc = ChildWrapper<T::Assoc>;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Child<A>` is not implemented for `<T as Parent>::Assoc`
    |
+   = note: required because of the requirements on the impl of `Child<A>` for `ChildWrapper<<T as Parent>::Assoc>`
 help: consider further restricting the associated type
    |
 LL | impl<A, T: Parent<Ty = A>> Parent for ParentWrapper<T> where <T as Parent>::Assoc: Child<A> {
    |                                                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: aborting due to 3 previous errors
+error: aborting due to previous error
 
 For more information about this error, try `rustc --explain E0277`.
diff --git a/src/test/ui/traits/cycle-cache-err-60010.rs b/src/test/ui/traits/cycle-cache-err-60010.rs
index cbddef082be..62d558fde88 100644
--- a/src/test/ui/traits/cycle-cache-err-60010.rs
+++ b/src/test/ui/traits/cycle-cache-err-60010.rs
@@ -28,7 +28,9 @@ struct SalsaStorage {
 }
 
 impl Database for RootDatabase {
-    type Storage = SalsaStorage; //~ ERROR overflow
+    // This would also be an error if we didn't abort compilation on the error
+    // above.
+    type Storage = SalsaStorage;
 }
 impl HasQueryGroup for RootDatabase {}
 impl<DB> Query<DB> for ParseQuery
diff --git a/src/test/ui/traits/traits-inductive-overflow-two-traits.rs b/src/test/ui/traits/traits-inductive-overflow-two-traits.rs
index 63dd1419200..463b55d8581 100644
--- a/src/test/ui/traits/traits-inductive-overflow-two-traits.rs
+++ b/src/test/ui/traits/traits-inductive-overflow-two-traits.rs
@@ -9,6 +9,7 @@ pub trait Magic {
 }
 impl<T: Magic> Magic for T {
     type X = Self;
+    //~^ ERROR E0277
 }
 
 fn check<T: Trait>() {}
diff --git a/src/test/ui/traits/traits-inductive-overflow-two-traits.stderr b/src/test/ui/traits/traits-inductive-overflow-two-traits.stderr
index f66cfce55c9..dbe0146cafa 100644
--- a/src/test/ui/traits/traits-inductive-overflow-two-traits.stderr
+++ b/src/test/ui/traits/traits-inductive-overflow-two-traits.stderr
@@ -1,5 +1,19 @@
+error[E0277]: `T` cannot be shared between threads safely
+  --> $DIR/traits-inductive-overflow-two-traits.rs:11:5
+   |
+LL |     type X: Trait;
+   |             ----- required by this bound in `Magic::X`
+...
+LL |     type X = Self;
+   |     ^^^^^^^^^^^^^^ `T` cannot be shared between threads safely
+   |
+help: consider further restricting this bound
+   |
+LL | impl<T: Magic + std::marker::Sync> Magic for T {
+   |               ^^^^^^^^^^^^^^^^^^^
+
 error[E0275]: overflow evaluating the requirement `*mut (): Magic`
-  --> $DIR/traits-inductive-overflow-two-traits.rs:19:5
+  --> $DIR/traits-inductive-overflow-two-traits.rs:20:5
    |
 LL | fn wizard<T: Magic>() { check::<<T as Magic>::X>(); }
    |              ----- required by this bound in `wizard`
@@ -7,6 +21,7 @@ LL | fn wizard<T: Magic>() { check::<<T as Magic>::X>(); }
 LL |     wizard::<*mut ()>();
    |     ^^^^^^^^^^^^^^^^^
 
-error: aborting due to previous error
+error: aborting due to 2 previous errors
 
-For more information about this error, try `rustc --explain E0275`.
+Some errors have detailed explanations: E0275, E0277.
+For more information about an error, try `rustc --explain E0275`.
diff --git a/src/test/ui/try-block/try-block-bad-type.stderr b/src/test/ui/try-block/try-block-bad-type.stderr
index 03d5d3661dd..dfc1c342a50 100644
--- a/src/test/ui/try-block/try-block-bad-type.stderr
+++ b/src/test/ui/try-block/try-block-bad-type.stderr
@@ -41,7 +41,7 @@ LL |     let res: i32 = try { 5 };
    |
    = note: required by `from_ok`
 
-error: aborting due to 5 previous errors
+error: aborting due to 6 previous errors
 
 Some errors have detailed explanations: E0271, E0277.
 For more information about an error, try `rustc --explain E0271`.