message: Candidate type may be nullptr
  Summary:
  Introduced by
  Sushan figures out the bug.
diff: @@ -538,6 +538,7 @@ class CodeTransformer final {
  extract_candidate_enum_type(env.get(insn->src(0)));
  if (m_enum_attrs.count(container)) {
  always_assert(candidate_type == nullptr || candidate_type == container);
  + candidate_type = container;
  } else if (!candidate_type) {
  return;
  }
  