https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81797
--- Comment #29 from Francois-Xavier Coudert <fxcoudert at gcc dot gnu.org> --- As suggested by Marc, I've removed the @ from include/Makefile.in, and removed the leading - for lines with LN_S. 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
