1 files changed, 13 insertions, 4 deletions
diff --git a/compiler/rustc_trait_selection/src/traits/query/type_op/custom.rs b/compiler/rustc_trait_selection/src/traits/query/type_op/custom.rs
index 6d8d2103f..5420caee3 100644
--- a/compiler/rustc_trait_selection/src/traits/query/type_op/custom.rs
+++ b/compiler/rustc_trait_selection/src/traits/query/type_op/custom.rs
@@ -5,6 +5,7 @@ use crate::traits::ObligationCtxt;
 use rustc_errors::ErrorGuaranteed;
 use rustc_infer::infer::region_constraints::RegionConstraintData;
 use rustc_middle::traits::query::NoSolution;
+use rustc_middle::ty::{TyCtxt, TypeFoldable};
 use rustc_span::source_map::DUMMY_SP;
 use rustc_span::Span;
 
@@ -24,9 +25,10 @@ impl<F> CustomTypeOp<F> {
     }
 }
 
-impl<'tcx, F, R: fmt::Debug> super::TypeOp<'tcx> for CustomTypeOp<F>
+impl<'tcx, F, R> super::TypeOp<'tcx> for CustomTypeOp<F>
 where
     F: FnOnce(&ObligationCtxt<'_, 'tcx>) -> Result<R, NoSolution>,
+    R: fmt::Debug + TypeFoldable<TyCtxt<'tcx>>,
 {
     type Output = R;
     /// We can't do any custom error reporting for `CustomTypeOp`, so
@@ -57,12 +59,16 @@ impl<F> fmt::Debug for CustomTypeOp<F> {
 
 /// Executes `op` and then scrapes out all the "old style" region
 /// constraints that result, creating query-region-constraints.
-pub fn scrape_region_constraints<'tcx, Op: super::TypeOp<'tcx, Output = R>, R>(
+pub fn scrape_region_constraints<'tcx, Op, R>(
     infcx: &InferCtxt<'tcx>,
     op: impl FnOnce(&ObligationCtxt<'_, 'tcx>) -> Result<R, NoSolution>,
     name: &'static str,
     span: Span,
-) -> Result<(TypeOpOutput<'tcx, Op>, RegionConstraintData<'tcx>), ErrorGuaranteed> {
+) -> Result<(TypeOpOutput<'tcx, Op>, RegionConstraintData<'tcx>), ErrorGuaranteed>
+where
+    R: TypeFoldable<TyCtxt<'tcx>>,
+    Op: super::TypeOp<'tcx, Output = R>,
+{
     // During NLL, we expect that nobody will register region
     // obligations **except** as part of a custom type op (and, at the
     // end of each custom type op, we scrape out the region
@@ -76,7 +82,7 @@ pub fn scrape_region_constraints<'tcx, Op: super::TypeOp<'tcx, Output = R>, R>(
     );
 
     let value = infcx.commit_if_ok(|_| {
-        let ocx = ObligationCtxt::new_in_snapshot(infcx);
+        let ocx = ObligationCtxt::new(infcx);
         let value = op(&ocx).map_err(|_| {
             infcx.tcx.sess.delay_span_bug(span, format!("error performing operation: {name}"))
         })?;
@@ -91,6 +97,9 @@ pub fn scrape_region_constraints<'tcx, Op: super::TypeOp<'tcx, Output = R>, R>(
         }
     })?;
 
+    // Next trait solver performs operations locally, and normalize goals should resolve vars.
+    let value = infcx.resolve_vars_if_possible(value);
+
     let region_obligations = infcx.take_registered_region_obligations();
     let region_constraint_data = infcx.take_and_reset_region_constraints();
     let region_constraints = query_response::make_query_region_constraints(