https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110168
Xi Ruoyao <xry111 at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |xry111 at gcc dot gnu.org --- Comment #4 from Xi Ruoyao <xry111 at gcc dot gnu.org> --- With GCC-13.1.0 and Glibc-2.37 we have: $ cc hw.c -D_FORTIFY_SOURCE In file included from /usr/include/bits/libc-header-start.h:33, from /usr/include/stdio.h:27, from hw.c:1: /usr/include/features.h:413:4: warning: #warning _FORTIFY_SOURCE requires compiling with optimization (-O) [-Wcpp] 413 | # warning _FORTIFY_SOURCE requires compiling with optimization (-O) | ^~~~~~~ It's enough to highlight the "issue". If there is no such warning, it's because the downstream distro is doing stupid thing and the distro maintainer should fix it.