https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105664
--- Comment #4 from Francois-Xavier Coudert <fxcoudert at gcc dot gnu.org> --- 1. I've reproduced it on x86_64-linux, so it's not a weird macOS mv bug 2. I have reasons to think (no hard proof, though) that it's a new bug: we're hitting it during Homebrew testing, but it wasn't the case before. Yet, this is confusing, because the install-driver target in gcc/Makefile.in has not been changed in years.