Example: #100399. This was fixed by adding stability attributes (#100418), but the general problem remains that #99573 was able to land. cc @dtolnay @yaahc <!-- TRIAGEBOT_START --> <!-- TRIAGEBOT_ASSIGN_START --> <!-- TRIAGEBOT_ASSIGN_DATA_START$${"user":"compiler-errors"}$$TRIAGEBOT_ASSIGN_DATA_END --> <!-- TRIAGEBOT_ASSIGN_END --> <!-- TRIAGEBOT_END -->
