https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65306
howarth at bromo dot med.uc.edu changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |howarth at bromo dot med.uc.edu --- Comment #6 from howarth at bromo dot med.uc.edu --- I don't see this problem with the same Xcode 6.1.1 and associated command line tools package installed on 10.9.4 as current gcc-4_9_branch... % ../gcc-4.9.3-20150227/configure --prefix=/Users/howarth/dist --enable-languages=c,c++ --with-gmp=/sw --with-libiconv-prefix=/sw --with-isl=/sw --with-cloog=/sw --with-mpc=/sw --with-system-zlib --x-includes=/usr/X11R6/include --x-libraries=/usr/X11R6/lib --enable-threads --enable-static bootstraps fine here. The fact that you aren't aren't using -with-gmp or --with-mpc is rather disconcerting as it suggests you have been installing into the system directories instead of /usr/local or /opt. If so, I would suggest reinstalling the OS to purge out anything you've installed in the system directories.