[Ltib] building multiple platforms, rpm cache

[Mike Goins]

I am trying to build specific configurations in ltib under continous
integration system using the command:
./ltib --batch --clobber --preconfig config/platform/iolite/defconfig-Iolite
(I know that platform does not exist in ltib yet, but bear with me)

Then I may have to build for another platform, so I argue another
platform after that:
./ltib --batch --clobber --preconfig config/platform/mpc8377/defconfig-8377

The first step I see that it removes all the rpms, caches those in a
directory, looks a time-stamp, and builds the new platform.

So far so good, it seems.  But when I switch back to the original platform:
./ltib --batch --clobber --preconfig config/platform/iolite/defconfig-Iolite

The rpm removal does not take place and the cached rpms are not used.
I can't quire figure out what I am missing.  Is --preconfig the
correct argument for this?

I looked at bin/autobuild_ltib to see how it does it, but it appear
that it expects a separate copy of ltib for each platform config.  I
just can't find a good way to integrate that method into a ci system.

Thanks