I just realized there's possibly another related problem. With gcc-PIE setting the gcc default to use -fPIE -pie, libgnat is build with -fPIE (and libgnat_pic.a with -fpic). Filed PR87938 - libgnat.a not compiled with -fno-PIC ( https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87938 ).