rpm scriptlet testing

[Andre Robatino]

Rpm scriptlet testing is not expected to be automated in the near future
(though eventually it really ought to be). I can test the PRE and POST
scriptlets by a yum reinstall. PREUN and POSTUN are both harder to test, and
more insidious since bugs appear even when updating to a fixed version. The
F19 release version of usbmuxd has a PREUN bug, so we will soon have a long
thread in the users list with stable users dealing with it. I don't know how
to test PREUN and POSTUN short of either having an available lower version
to downgrade to (maybe impossible in rawhide) or removing and reinstalling
the rpm with --force (maybe a bad idea if the running system depends on it).
What is the best way to test all four scriptlets manually, since we won't
have automation for it soon?