git checkout

[Ralf Wildenhues]

Somehow a git (tarball?[1]) checkout of Autoconf sometimes manages to
get a version of UNKNOWN into its .version file.  Presumably that is on
systems without git installed (or listed as dependency).  See on the
hydra build: <http://hydra.nixos.org/build/256086>

My point is, the error that follows is quite unintuitive, and the issue
itself is worth fixing, too, I guess.  Maybe store in git a file
containing at least the latest stable release number, so we can fall
back to something like 2.65-dirty rather than UNKNOWN?

Thanks,
Ralf

[1] git/cgit allows you to pull snapshot tarballs containing the files
of some git commit.