Temporary fix for unknown expectations

crates/hir_ty/src/infer.rs

@@ -395,6 +395,10 @@ fn push_obligation(&mut self, o: DomainGoal) {
     }
 
     fn unify(&mut self, ty1: &Ty, ty2: &Ty) -> bool {
+        // TODO handle expectations properly
+        if ty2.is_unknown() {
+            return true;
+        }
         self.table.unify(ty1, ty2)
     }
 

crates/hir_ty/src/infer/coerce.rs

@@ -19,6 +19,10 @@ impl<'a> InferenceContext<'a> {
     /// Unify two types, but may coerce the first one to the second one
     /// using "implicit coercion rules" if needed.
     pub(super) fn coerce(&mut self, from_ty: &Ty, to_ty: &Ty) -> bool {
+        // TODO handle expectations properly
+        if to_ty.is_unknown() {
+            return true;
+        }
         let from_ty = self.resolve_ty_shallow(from_ty).into_owned();
         let to_ty = self.resolve_ty_shallow(to_ty);
         match self.coerce_inner(from_ty, &to_ty) {