2 files changed, 10 insertions, 2 deletions
diff --git a/compiler/rustc_typeck/src/check/check.rs b/compiler/rustc_typeck/src/check/check.rs
index 5362ca8d719..33682177253 100644
--- a/compiler/rustc_typeck/src/check/check.rs
+++ b/compiler/rustc_typeck/src/check/check.rs
@@ -12,12 +12,13 @@ use rustc_hir::lang_items::LangItem;
 use rustc_hir::{def::Res, ItemKind, Node, PathSegment};
 use rustc_infer::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind};
 use rustc_infer::infer::{RegionVariableOrigin, TyCtxtInferExt};
+use rustc_infer::traits::Obligation;
 use rustc_middle::hir::nested_filter;
 use rustc_middle::ty::fold::TypeFoldable;
 use rustc_middle::ty::layout::{LayoutError, MAX_SIMD_LANES};
 use rustc_middle::ty::subst::GenericArgKind;
 use rustc_middle::ty::util::{Discr, IntTypeExt};
-use rustc_middle::ty::{self, ParamEnv, Ty, TyCtxt};
+use rustc_middle::ty::{self, ParamEnv, ToPredicate, Ty, TyCtxt};
 use rustc_session::lint::builtin::{UNINHABITED_STATIC, UNSUPPORTED_CALLING_CONVENTIONS};
 use rustc_span::symbol::sym;
 use rustc_span::{self, MultiSpan, Span};
@@ -674,6 +675,13 @@ fn check_opaque_meets_bounds<'tcx>(
             }
         }
 
+        // Additionally require the hidden type to be well-formed with only the generics of the opaque type.
+        // Defining use functions may have more bounds than the opaque type, which is ok, as long as the
+        // hidden type is well formed even without those bounds.
+        let predicate =
+            ty::Binder::dummy(ty::PredicateKind::WellFormed(hidden_type.into())).to_predicate(tcx);
+        inh.register_predicate(Obligation::new(misc_cause, param_env, predicate));
+
         // Check that all obligations are satisfied by the implementation's
         // version.
         let errors = inh.fulfillment_cx.borrow_mut().select_all_or_error(&infcx);
diff --git a/compiler/rustc_typeck/src/check/regionck.rs b/compiler/rustc_typeck/src/check/regionck.rs
index 513e8576f2d..e18cb31acbd 100644
--- a/compiler/rustc_typeck/src/check/regionck.rs
+++ b/compiler/rustc_typeck/src/check/regionck.rs
@@ -171,8 +171,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
     /// Region checking during the WF phase for items. `wf_tys` are the
     /// types from which we should derive implied bounds, if any.
+    #[instrument(level = "debug", skip(self))]
     pub fn regionck_item(&self, item_id: hir::HirId, span: Span, wf_tys: FxHashSet<Ty<'tcx>>) {
-        debug!("regionck_item(item.id={:?}, wf_tys={:?})", item_id, wf_tys);
         let subject = self.tcx.hir().local_def_id(item_id);
         let mut rcx = RegionCtxt::new(self, item_id, Subject(subject), self.param_env);
         rcx.outlives_environment.add_implied_bounds(self, wf_tys, item_id, span);