https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67002
--- Comment #25 from John Paul Adrian Glaubitz <glaubitz at physik dot fu-berlin.de> --- Ok, this seems to have been fixed: Comparing stages 2 and 3 warning: gcc/cc1objplus-checksum.o differs warning: gcc/cc1-checksum.o differs warning: gcc/cc1plus-checksum.o differs warning: gcc/cc1obj-checksum.o differs Comparison successful. gcc-5 is still building though and we might run into another issue, but cross your fingers :).