[lug] How to change rpm package names

[Michael Hirsch]

Suppose you've released a package named foo-1.rpm and for various
reasons your next version will be bar-2.rpm.  It is possible to do it
so that upgrades don't choke?

I'd like yum to somehow look at the bar rpm and see that it is an
upgrade of foo and automatically install bar and remove foo.

I thought I'd done this before, but I've lost the trick.  I thought I
recalled an "obsolete" declaration in the spec file, but I can't find
anything about that anymore.

Thanks,

Michael