http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54918
--- Comment #6 from Ian Lance Taylor <ian at airs dot com> 2012-10-23 18:14:04 UTC --- Jakub Jelinek asked that I not change the libgo SONAME now that GCC 4.7 has been released. So libgo in GCC 4.6 and 4.7 use the same SONAME but are incompatible, and that is just the way it is. Sorry.