https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63758
--- Comment #8 from Iain Sandoe <iains at gcc dot gnu.org> --- posted as https://gcc.gnu.org/ml/gcc-patches/2015-09/msg00447.html with Eric's suggested move of environ.h -> include/ checked with a bootstrap on darwin12 that libiberty.a only contains references to _NSGetEnviron().