https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86450
--- Comment #17 from Jonathan Wakely <redi at gcc dot gnu.org> --- The problem is that gfortran development is dependent on a gcc-wide build mode which affects more than just gfortran. There's no good reason that libstdc++ should be a blocker for you (for the record, the -Wabi flag has been present for years, and the -Werror consequence of maintainer mode has been there for years too, what changed was not in libstdc++ but g++). If you had (for example) a --enable-gfortran-maintainer-mode option that triggered the m4 regeneration then you wouldn't need to alter the build options for the rest of gcc. Or a makefile target that regenerated the files, without needing to enable maintainer mode globally. Or some other solution that was under your control and specific to your subsystem, that didn't depend on other components that you don't need to depend on. That aside, I think not setting -Werror in libstdc++ for maintainer mode is better than simply removing warning options. But I'm on holiday and not going to commit anything myself, so do whatever you need to do. I'll put -Wabi=N back later if we decide it should be there, with a suitable value of N so it doesn't give the current warning.
