3 files changed, 39 insertions, 12 deletions
diff --git a/compiler/rustc_middle/src/ty/print/pretty.rs b/compiler/rustc_middle/src/ty/print/pretty.rs
index b11a54d5dcb..742005e245f 100644
--- a/compiler/rustc_middle/src/ty/print/pretty.rs
+++ b/compiler/rustc_middle/src/ty/print/pretty.rs
@@ -744,6 +744,7 @@ pub trait PrettyPrinter<'tcx>:
                     p!(print_def_path(did, substs));
                     if !substs.as_closure().is_valid() {
                         p!(" closure_substs=(unavailable)");
+                        p!(write(" substs={:?}", substs));
                     } else {
                         p!(" closure_kind_ty=", print(substs.as_closure().kind_ty()));
                         p!(
diff --git a/compiler/rustc_trait_selection/src/traits/project.rs b/compiler/rustc_trait_selection/src/traits/project.rs
index db8a6d96204..b8c66931cbe 100644
--- a/compiler/rustc_trait_selection/src/traits/project.rs
+++ b/compiler/rustc_trait_selection/src/traits/project.rs
@@ -1734,7 +1734,7 @@ fn confirm_callable_candidate<'cx, 'tcx>(
         ty: ret_type,
     });
 
-    confirm_param_env_candidate(selcx, obligation, predicate, false)
+    confirm_param_env_candidate(selcx, obligation, predicate, true)
 }
 
 fn confirm_param_env_candidate<'cx, 'tcx>(
@@ -1754,8 +1754,18 @@ fn confirm_param_env_candidate<'cx, 'tcx>(
     );
 
     let cache_projection = cache_entry.projection_ty;
-    let obligation_projection = obligation.predicate;
     let mut nested_obligations = Vec::new();
+    let obligation_projection = obligation.predicate;
+    let obligation_projection = ensure_sufficient_stack(|| {
+        normalize_with_depth_to(
+            selcx,
+            obligation.param_env,
+            obligation.cause.clone(),
+            obligation.recursion_depth + 1,
+            obligation_projection,
+            &mut nested_obligations,
+        )
+    });
     let cache_projection = if potentially_unnormalized_candidate {
         ensure_sufficient_stack(|| {
             normalize_with_depth_to(
@@ -1771,6 +1781,8 @@ fn confirm_param_env_candidate<'cx, 'tcx>(
         cache_projection
     };
 
+    debug!(?cache_projection, ?obligation_projection);
+
     match infcx.at(cause, param_env).eq(cache_projection, obligation_projection) {
         Ok(InferOk { value: _, obligations }) => {
             nested_obligations.extend(obligations);
diff --git a/compiler/rustc_trait_selection/src/traits/select/confirmation.rs b/compiler/rustc_trait_selection/src/traits/select/confirmation.rs
index a36cb1358b6..a4e2e502833 100644
--- a/compiler/rustc_trait_selection/src/traits/select/confirmation.rs
+++ b/compiler/rustc_trait_selection/src/traits/select/confirmation.rs
@@ -620,23 +620,37 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
             _ => bug!("closure candidate for non-closure {:?}", obligation),
         };
 
+        let obligation_predicate = obligation.predicate.to_poly_trait_ref();
+        let Normalized { value: obligation_predicate, mut obligations } =
+            ensure_sufficient_stack(|| {
+                normalize_with_depth(
+                    self,
+                    obligation.param_env,
+                    obligation.cause.clone(),
+                    obligation.recursion_depth + 1,
+                    obligation_predicate,
+                )
+            });
+
         let trait_ref = self.closure_trait_ref_unnormalized(obligation, substs);
-        let Normalized { value: trait_ref, mut obligations } = ensure_sufficient_stack(|| {
-            normalize_with_depth(
-                self,
-                obligation.param_env,
-                obligation.cause.clone(),
-                obligation.recursion_depth + 1,
-                trait_ref,
-            )
-        });
+        let Normalized { value: trait_ref, obligations: trait_ref_obligations } =
+            ensure_sufficient_stack(|| {
+                normalize_with_depth(
+                    self,
+                    obligation.param_env,
+                    obligation.cause.clone(),
+                    obligation.recursion_depth + 1,
+                    trait_ref,
+                )
+            });
 
         debug!(?closure_def_id, ?trait_ref, ?obligations, "confirm closure candidate obligations");
 
+        obligations.extend(trait_ref_obligations);
         obligations.extend(self.confirm_poly_trait_refs(
             obligation.cause.clone(),
             obligation.param_env,
-            obligation.predicate.to_poly_trait_ref(),
+            obligation_predicate,
             trait_ref,
         )?);