Merge pull request #22135 from ChayimFriedman2/mono-infer

ShoyuVanilla · web-flow · commit 4295875fb21d · 2026-04-22T07:04:24.000Z
fix: Suppress infer vars in monomorphization
diff --git a/crates/hir-ty/src/mir/monomorphization.rs b/crates/hir-ty/src/mir/monomorphization.rs
@@ -65,6 +65,9 @@ impl<'db> FallibleTypeFolder<DbInterner<'db>> for Filler<'db> {
                         ty,
                     )
                     .map_err(|_| MirLowerError::NotSupported("can't normalize alias".to_owned()))?;
+                // Normalization could introduce infer vars (for example, if the alias cannot be normalized),
+                // and we must not have infer vars in the body.
+                let ty = ty.replace_infer_with_error(self.infcx.interner);
                 ty.try_super_fold_with(self)
             }
             TyKind::Param(param) => Ok(self

Original file line number	Diff line number	Diff line change
`@@ -65,6 +65,9 @@ impl<'db> FallibleTypeFolder<DbInterner<'db>> for Filler<'db> {`
`65`	`65`	`ty,`
`66`	`66`	`)`
`67`	`67`	`.map_err(\|_\| MirLowerError::NotSupported("can't normalize alias".to_owned()))?;`
	`68`	`+ // Normalization could introduce infer vars (for example, if the alias cannot be normalized),`
	`69`	`+ // and we must not have infer vars in the body.`
	`70`	`+ let ty = ty.replace_infer_with_error(self.infcx.interner);`
`68`	`71`	`ty.try_super_fold_with(self)`
`69`	`72`	`}`
`70`	`73`	`TyKind::Param(param) => Ok(self`