I updated my GCC to a more recent version a day ago, since Apple's Xcode Tools only provide GCC 4.0 and the current release of GNU's GCC is 4.2. I successfully achieved this, but now I run into a problem when trying to build NumPy: gcc: unrecognized option '-no-cpp-precomp' cc1: error: unrecognized command line option "-arch" cc1: error: unrecognized command line option "-arch" cc1: error: unrecognized command line option "-Wno-long-double" gcc: unrecognized option '-no-cpp-precomp' cc1: error: unrecognized command line option "-arch" cc1: error: unrecognized command line option "-arch" cc1: error: unrecognized command line option "-Wno-long-double" Upon investigation into the matter, I found out that these options (no-cpp-precomp and Wno-long-double) are only valid in Apple's GCC and not the regular GNU release. Yet it seems NumPy automatically assumes Apple's GCC is being used when it realizes the target is OS X. Is there a way around this, or at least some way to specify Apple's GCC? NumPy is the only package I've tried building so far that has a problem with this.