https://gcc.gnu.org/bugzilla/show_bug.cgi?id=72823
--- Comment #8 from Jakub Jelinek <jakub at gcc dot gnu.org> --- I guess the thing is that ENABLE_ASSERT_CHECKING is never defined while building libcpp, it is simply not handled by libcpp/configure* and not stored in libcpp/config*. So, either it could use CHECKING_P instead, or the configury needs to be changed.
