https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87243
--- Comment #1 from Iain Sandoe <iains at gcc dot gnu.org> --- I am strongly against making GCC's configure depend on xcrun. It is quite possible that GCC could be used, for example, with PureDarwin - or on systems without any Xcode install (using headers built from the OpenSource packages). So, yes we have to find a solution to finding the headers, but no, (at least I don't agree) that trying into yet another tool we don't control is that solution.