dist-git proof of concept phase 2 ready for testing

[Roland McGrath]

> I understand the use case, I'm still not super keen on having official
> built packages come out of a branch.  Makes discovery somewhat
> difficult, and leads to problems if we have to bump+build something and
> don't realize that the real live code is actually on a branch.

Surely all previous builds will be easy to "discover" in koji and that will
tell you the exact commit id.  AIUI there should be an automagic git tag
pushed by koji so that just directly in git alone it is trivial and
reliable to find the commit matching a given build.  In git the idea of a
branch is not inherently a permanent thing, and only the ancestry graph of
a particular commit is truly meaningful as historical information.  Just
the commit id of interest is what you need to ascertain whether it is the
head or ancestor of which branches at the time you ask the question.


Thanks,
Roland