https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87672
--- Comment #11 from jamespharvey20 at gmail dot com --- I can confirm applying Bernd Edlinger's "2018-10-21 18:16:41 UTC" patch on current trunk prevents all 3 reported errors, and allows using CPPFLAGS="-D_FORTIFY_SOURCE=2" and the additions of "-O2" into {libiberty,gcc}/configure. Obviously, no one is obligated to provide me any insight. (Of course, no one was even obligated to fix this, thanks Bernd for doing so!) I'd love hearing: (1) how stage 2 was succeeding but stage 3 was failing, in a short "explain it to me like I can compile and use gcc and know the theory of bootstrapping, but have no idea what this patch is really doing"; and (2) if this patch fixes a somewhat "hidden/silent" bug that needed to be fixed even for people not compiling using these compilation flags, or if the fix is limited in scope to those using these flags who would run into the compilation error.