It would be nice if koji ran createrepo in .../packages/name/version/release
when a build finishes, and the same in scratch/user/task dirs. It should be
quick and cheap since it's just a few rpms (I'm suggesting one run at the
top covering all arch's). Especially for packages with many subpackages, it
would be real handy to be able to try a build using a one-off .repo file
pointed at http://koji.fedoraproject.org/packages/foo/v/r/
--enablerepo, where one now downloads all the rpms and uses rpm by hand.