https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105819
--- Comment #9 from Jakub Jelinek <jakub at gcc dot gnu.org> --- (In reply to Jonathan Wakely from comment #6) > Try it again without using a directory called "_Source/_12,1,x" Say _Source/_12.1.x would work, dot is often used separator in filenames that is known to work.