https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70594
--- Comment #26 from Jason Merrill <jason at gcc dot gnu.org> --- (In reply to Jason Merrill from comment #25) > Created attachment 38245 [details] > Patch to not discard copies > > This seems like a minimal fix; does it in fact fix the bug? With this patch gengtype seems to assign gt_ggc_mx(tree&) to cp/constexpr.o, breaking cc1 link. I'm not going to try to fix that now, though someone else is welcome to.