https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81797
--- Comment #31 from Misty De Meo <misty at brew dot sh> --- > 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 . For what it's worth, Apple's response was: "We analyzed the issue and determined the problem to be a latent bug in gcc’s build system that is revealed by changes in macOS High Sierra. The FSF will need up issue a fix in gcc."
