https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81797
Francois-Xavier Coudert <fxcoudert at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Component|target |libstdc++ --- Comment #18 from Francois-Xavier Coudert <fxcoudert at gcc dot gnu.org> --- Definitely not "target" if it is seen on other platforms too. Adding ".NOTPARALLEL: install-headers" to the libstdc++ Makefile fixes it perfectly, from what we can see on our apple-darwin test machines. We've now had dozens of compilations of GCC with no error, once that is applied. Without the patch, about ~70% of parallel compilations fail, on machines ranging from 2 to 8 cores. I'd like to suggest ".NOTPARALLEL: install-headers" to be considered as official patch.