use `TypingEnv` when no `infcx` is available

the behavior of the type system not only depends on the current
assumptions, but also the currentnphase of the compiler. This is
mostly necessary as we need to decide whether and how to reveal
opaque types. We track this via the `TypingMode`.

1 files changed, 3 insertions, 2 deletions

diff --git a/compiler/rustc_trait_selection/src/traits/mod.rs b/compiler/rustc_trait_selection/src/traits/mod.rs
index fe90066b4e7..c0603c06d42 100644
--- a/compiler/rustc_trait_selection/src/traits/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/mod.rs
@@ -611,11 +611,12 @@ pub fn try_evaluate_const<'tcx>(
             //
             // FIXME: `const_eval_resolve_for_typeck` should probably just set the env to `Reveal::All`
             // instead of having this logic here
-            let env = tcx.erase_regions(param_env).with_reveal_all_normalized(tcx);
+            let typing_env =
+                tcx.erase_regions(infcx.typing_env(param_env)).with_reveal_all_normalized(tcx);
             let erased_uv = tcx.erase_regions(uv);
 
             use rustc_middle::mir::interpret::ErrorHandled;
-            match tcx.const_eval_resolve_for_typeck(env, erased_uv, DUMMY_SP) {
+            match tcx.const_eval_resolve_for_typeck(typing_env, erased_uv, DUMMY_SP) {
                 Ok(Ok(val)) => Ok(ty::Const::new_value(
                     tcx,
                     val,