Hello all. This is fascinating in that it seems to be quite emphatic in the message : . . . rm -f stage_current gmake[3]: Leaving directory '/usr/local/build/gcc-7.2.0_SunOS5.10_sparc64vii+.002' Comparing stages 2 and 3 warning: gcc/cc1obj-checksum.o differs warning: gcc/cc1-checksum.o differs warning: gcc/cc1objplus-checksum.o differs warning: gcc/cc1plus-checksum.o differs Bootstrap comparison failure! gcc/cfganal.o differs gcc/vec.o differs . . . many many lines about other "differs" . . . zlib/libz_a-gzwrite.o differs zlib/libz_a-gzread.o differs gmake[2]: *** [Makefile:28094: compare] Error 1 gmake[2]: Leaving directory '/usr/local/build/gcc-7.2.0_SunOS5.10_sparc64vii+.002' gmake[1]: *** [Makefile:28074: stage3-bubble] Error 2 gmake[1]: Leaving directory '/usr/local/build/gcc-7.2.0_SunOS5.10_sparc64vii+.002' gmake: *** [Makefile:28137: bootstrap] Error 2 So .. wow. Could this be because I have different stage languages and stage1-checking selected? --enable-languages=ada,c,c++,fortran,go,objc,obj-c++ --enable-stage1-languages=c,c++ --enable-stage1-checking=misc or perhaps some other mystery ? Dennis