https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92061
--- Comment #6 from Jakub Jelinek <jakub at gcc dot gnu.org> --- That said, I can't reproduce on x86_64-linux with clang version 10.0.0 (trunk 374035) if I build build/gencondmd.o, both with -O0 or -O2, nm -u shows just U ferror U fflush U printf U putc U puts U stdout which is expected.