https://gcc.gnu.org/bugzilla/show_bug.cgi?id=119357
--- Comment #1 from Sam James <sjames at gcc dot gnu.org> --- Created attachment 60808 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=60808&action=edit mask_test.ii.notrait.xz Preprocessed source from -D_GLIBCXX_DO_NOT_USE_BUILTIN_TRAITS, sorry for forgetting that.