https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80913
--- Comment #6 from Nathan Sidwell <nathan at gcc dot gnu.org> --- I have a small reproducer, regardless of bitsize: extern int meminfo (); struct meminfo {}; void frob () { meminf (); } stat hack when the struct decl is last. It looks like a patch I have on the modules branch is not as orthogonal to this as I thought.