`QueryNormalizer` bug on ambiguity

diff --git a/compiler/rustc_trait_selection/src/traits/query/normalize.rs b/compiler/rustc_trait_selection/src/traits/query/normalize.rs
index eccfb3477b9dd00e6726bc8f3a3033d528dca021..449d7a7b47b1fcd82042d7156c0cb876c0ab25a2 100644 (file)
--- a/compiler/rustc_trait_selection/src/traits/query/normalize.rs
+++ b/compiler/rustc_trait_selection/src/traits/query/normalize.rs
@@ -254,7 +254,7 @@ fn try_fold_ty(&mut self, ty: Ty<'tcx>) -> Result<Ty<'tcx>, Self::Error> {
                 let result = tcx.normalize_projection_ty(c_data)?;
                 // We don't expect ambiguity.
                 if result.is_ambiguous() {
-                    return Err(NoSolution);
+                    bug!("unexpected ambiguity: {:?} {:?}", c_data, result);
                 }
                 let InferOk { value: result, obligations } =
                     self.infcx.instantiate_query_response_and_region_obligations(
@@ -293,7 +293,7 @@ fn try_fold_ty(&mut self, ty: Ty<'tcx>) -> Result<Ty<'tcx>, Self::Error> {
                 let result = tcx.normalize_projection_ty(c_data)?;
                 // We don't expect ambiguity.
                 if result.is_ambiguous() {
-                    return Err(NoSolution);
+                    bug!("unexpected ambiguity: {:?} {:?}", c_data, result);
                 }
                 let InferOk { value: result, obligations } =
                     self.infcx.instantiate_query_response_and_region_obligations(