UBSan is not exhaustive. There are large and important cases of UB it cannot detect. There are also cases where the compiler simply won't insert the proper chec

UBSan is not exhaustive. There are large and important cases of UB it cannot detect. There are also cases where the compiler simply won't insert the proper checks even for detectable issues. None of the sanitizers are broadly intended for production use either, though UBSan offers a specific mode you can select (fsanitize-minimal-runtime) that's appropriate for some production uses.