http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38339
--- Comment #18 from Ralf Wildenhues <rwild at gcc dot gnu.org> 2010-10-02 05:34:16 UTC --- Ah, sorry. The sed script was meant for the toplevel source directory. Your .../libmudflap/config.log however looks like configure did compute the maximum command line length correctly. Let's hope the shell trace log will provide more clues. Thanks.