https://gcc.gnu.org/bugzilla/show_bug.cgi?id=57792
--- Comment #11 from howarth at bromo dot med.uc.edu --- (In reply to Hin-Tak Leung from comment #9) > Did the change make it into 4.9.2? I recently tried that > and found that I need the explicit --sysroot: > https://gcc.gnu.org/ml/gcc-testresults/2014-11/msg00268.html > Also, if you can't find /usr/include on OS X, that means you need to install the Command Line Tools with 'xcode-select --install'.