https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87750
--- Comment #10 from Alexandre Oliva <aoliva at gcc dot gnu.org> --- ... and it looks like lookup/using44.C really wants the USING_DECL from lookup_member; the function overloads are not template dependent, and as a result we perform overload resolution only among them, leaving out the function decl we should select through the using decl. Ugh. I guess this simple, hackish approach won't work. I'll have to either figure out a way to indicate in the returned using decl (before the change) that some other overload is a template, or return the entire overload and adjust places that don't like that, or use an alternate lookup where we want to get the overloads, or just to tell whether there's any template among them. ugh :-/ but first, some sleep :-)
