https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81797
--- Comment #30 from Marc Glisse <glisse at gcc dot gnu.org> --- (In reply to Francois-Xavier Coudert from comment #29) > The result of "make -d --trace -j8 all-target-libstdc++-v3", in a build > where x86_64-apple-darwin17.0.0/libstdc++-v3 was entirely removed, can be > found here: > https://gist.github.com/fxcoudert/b621465a794d968593bc7ed90c0fc1fb make's I/O is not exactly a reliable way to debug multithreading issues, but the output looks right to me. If --disable-libstdcxx-pch works (does it?), and until someone can investigate more, I'd be tempted to consider it a mac bug and recommend that option in https://gcc.gnu.org/install/specific.html .
