https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91618
--- Comment #3 from Marek Polacek <mpolacek at gcc dot gnu.org> --- So the problem is in set_decl_namespace. We are called with decl=f, scope=::, friendp=true. It used to have - /* Writing "int N::i" to declare a variable within "N" is invalid. */ - if (scope == current_namespace) - { - if (at_namespace_scope_p ()) - error ("explicit qualification in declaration of %qD", - decl); - return; - } so before r249385 we returned without an error but now we look "f" up, find a TEMPLATE_DECL, which decls_match says doesn't match the FUNCTION_DECL "f", so we issue the not_found error. Nathan, any ideas?