http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50028
--- Comment #5 from Jonathan Wakely <redi at gcc dot gnu.org> 2011-08-09 14:39:44 UTC --- that last link should be http://gcc.gnu.org/wiki/VerboseDiagnostics#undefined_reference_to_.60S::a.27 (I'm not sure why the "Permalink" doesn't work)