https://gcc.gnu.org/bugzilla/show_bug.cgi?id=119510
--- Comment #11 from Jakub Jelinek <jakub at gcc dot gnu.org> --- I don't see how we could do the regeneration without actually building something unless we want to duplicate everything (in the posted patch, the libffi.info regeneration is an example of duplication, the rest just uses a make target). We need something that will at least configure gcc etc. We certainly can --disable-bootstrap, that will significantly speed it up.