http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60961
--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> --- Older versions of GCC have .texi files that are incompatible with the current version of texinfo. GCC 4.6 is no longer maintained or supported, so this is not going to be fixed now. You can workaround the problem by adding MISSING=texinfo to the GCC configure command.
