http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54191
--- Comment #5 from Paolo Carlini <paolo.carlini at oracle dot com> 2012-08-07 14:36:19 UTC --- For the cases where we are producing inaccessible base diagnostics in SFINAE context, the issue is that lookup_base is called by functions getting a complain argument always in the same way irrespective of complain. Not sure at the moment if simply changing the callers to pass what they are currently passing | ba_quiet whenever !(complain & tf_error) is enough or there are subtleties.
