GUB problems with git describe

[Graham Percival]

We're currently getting a shallow clone of the lilypond source.  In
test-lily/upload.py, this command is executed:
  cd downloads/lilypond/git && git describe --abbrev=39
git.sv.gnu.org/lilypond.git/master
but it fails with:
  fatal: cannot describe '834700852f25a6ade4a2f8efe2b13bc71278d3a3'
(this is used to construct the tag command-line)

I can work-around the problem by adding --always to the git describe
command-line, but then we end up with tags like this:
  git tag -m "release of lilypond
834700852f25a6ade4a2f8efe2b13bc71278d3a (2.13.4-0)"
"gub-release-lilypond-2.13.4-0"

1)  Do we care if the tag comment looks like this?
2)  If not, can anybody suggest a better way of fixing the git
describe command-line?

Jan and I have no particular opinions on the above matters.  Or
rather, I don't think it matters what the tag looks like, but I agreed
when he pointed out that the --always was an ugly hack and that we
should consult others for a better fix.

Cheers,
- Graham