https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87865
--- Comment #2 from ro at CeBiTec dot Uni-Bielefeld.DE <ro at CeBiTec dot Uni-Bielefeld.DE> --- > --- Comment #1 from Iain Buclaw <ibuclaw at gdcproject dot org> --- > This is part of the dmd frontend which as no interaction with gcc. So > gcc_unreachable() can't be used here. I see. However, if upstream dmc were built with similar warning options than gcc, the problem would exist there as well. > Sounds like some independent compatibility layer is required here instead. That's certainly an option. Among others, what to do here depends on how prevalent the problem is: if Solaris 10 is the only OS affected and the other pre-Solaris 11.4 issues (especially PR d/87865) cannot be resolved for the GCC 9 release, one might as well close the bug as WONTFIX given Solaris 10 is obsoleted in GCC 9.