> as my cursory searches show, one needs to have a "greeter" installed

Thanks for telling me, I had not heard of "greeter"s (embarrassed). Even though I remember FC6. Your advice is most welcome.

Black screen .. that was my problem, and I was deep into X11 logs trying to find the fix. Do you think there should be a dependency so a greeter of some sort will normally get installed? I am spoiled from a few years of using the slick Ubuntu UI's. Now that may change, as I hear of drastic changes in that camp.

Also, gtk could be a bit more defensive. Maybe I should get involved. The design probably uses Dependency Injection, and I would be inclined to code in some checks so that a friendly message goes in the log before a crash due to a missing / null dependency. I have done c++ UI code in the past, but I might be a bit rusty.
Cheers --Rick
--
Sorry for being brief. Alternate email is rickleir at yahoo dot com