http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60830
--- Comment #2 from Mikael Pettersson <mikpelinux at gmail dot com> --- I'm getting a different error bootstrapping the 4.9.0 RC on Cygwin: checking for C compiler default output file name... configure: error: in `/home/mikpe/objdir/i686-pc-cygwin/libgcc': configure: error: C compiler cannot create executables See `config.log' for more details. Makefile:14037: recipe for target 'configure-stage2-target-libgcc' failed make[2]: *** [configure-stage2-target-libgcc] Error 77 make[2]: Leaving directory '/home/mikpe/objdir' Makefile:16771: recipe for target 'stage2-bubble' failed make[1]: *** [stage2-bubble] Error 2 make[1]: Leaving directory '/home/mikpe/objdir' Makefile:16974: recipe for target 'bootstrap' failed make: *** [bootstrap] Error 2 Inspecting i686-pc-cygwin/libgcc/config.log shows a number of failed attempts to run gcc/xgcc: xgcc: error: unrecognized command line option '-isystem' xgcc: error: unrecognized command line option '-v' which eventually causes configure to give up. This is with cygwin-1.7.28 (32-bit), Windows 7 (64-bit), Core-i7.