------- Comment #4 from iains at gcc dot gnu dot org 2010-09-23 09:34 ------- this appears to be to do with the driver construction of a default macosx-version-min.
./gcc/xgcc -Bgcc -dumpspecs => bus error ./gcc/xgcc -Bgcc -dumpspecs -mmacosx-version-min=10.5 => completes normally. Initial debugging suggests that the constructed option is being flagged as error=4 (wrong language) -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45751
