https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114730
--- Comment #3 from Joseph S. Myers <jsm28 at gcc dot gnu.org> --- When implementing C23 enums with fixed underlying types I tried to ensure that enums with underlying type bool were handled consistently with bool (cf. bug 96496 where they're not always handled consistently for C++) but it seems I missed this vector_size check.