https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66521
--- Comment #7 from Jonathan Wakely <redi at gcc dot gnu.org> --- (In reply to Eric Gallager from comment #5) > this one; I think I had to pass the '--disable-libstdcxx-filesystem-ts' flag > to configure last time to get past it... I'll open a new PR about it. Please do, I'm planning to backport the Filesystem TS for GCC 5.3 so if it breaks the bootstrap on darwin I'd like to know the details.