Re: git checkout

[Bruno Haible]

[Original problem report in [1].]

> See on the hydra build:<http://hydra.nixos.org/build/256086>

Hydra creates its tarballs not directly from the git checkout, but by running
in particular "make dist" in the git checkout.[2] This has caused problems
also in other packages.

Specifically in autoconf: In this build log [3] you can see that
'git-version-gen' was complaining loudly "WARNING: .tarball-version seems
to be damaged".

The .tarball-version file contained 'UNKNOWN' after the Makefile.am rule
had blindly written git-version-gen's output into it:

  dist-hook:
          echo $(VERSION) > $(distdir)/.tarball-version

Maybe this rule should test the contents of $(VERSION) before writing it
into .tarball-version ?

> Or more simply, cat .prev-version
> 
> Perhaps this is something that build-aux/git-version-gen should attempt to
> use as a fallback before returning UNKNOWN?

This would make git-version-gen dependent on particular package structure
and file naming conventions. Currently, git-version-gen has only two
prerequisites:
  1) You need to run it in a git checkout,
  2) You need to pass it a filename as argument.
IMO, it should stay this way. Things that depend on package structure
belong in the package's Makefile.am.

But first, has anyone analyzed why git-version-gen failed at all in [3]?
The message
  fatal: cannot describe 'a2889ee464562b0b91c1bd6dd00d846ce4b022a0'
indicates some setup or build script problem on Hydra's side.

Bruno

[1] http://lists.gnu.org/archive/html/bug-autoconf/2010-01/msg00042.html
[2] http://lists.gnu.org/archive/html/bug-libunistring/2009-12/msg00008.html
[3] http://hydra.nixos.org/build/256083/log/raw