https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63610
--- Comment #9 from howarth at bromo dot med.uc.edu --- Alternatively, you can just make sure you don't set MACOSX_DEPLOYMENT_TARGET in your shell. Also mote that gmp, mpfr and mpc also suffer from this bug and, if built on 10.10, should either have their configure scripts patched or regenerated with the fixed libtool.
