https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79348
--- Comment #9 from Jonathan Wakely <redi at gcc dot gnu.org> --- I don't think that commit is related. Those symbols where added by r232454 and are defined when this condition is true: +#if __cplusplus >= 201103L && _GLIBCXX_USE_CXX11_ABI \ + && _GLIBCXX_USE_DUAL_ABI && __cpp_transactional_memory >= 201505L \ + && !_GLIBCXX_FULLY_DYNAMIC_STRING && __GXX_WEAK__ \ + && _GLIBCXX_USE_ALLOCATOR_NEW
