Open Stack

Hi all,

I've been investigating why the tests break with
GitPython 0.3.2.1, and I've tracked the problem down
to a commit in GitPython, but I'm not sure where
the fix should go.

In GitPython, commit ff13922f [1], a call to finalize_process
was added into the Repo class. finalize_process
is there to make sure the call to the git binary is
shut down cleanly, but it also picks up exit code 128
and re-raises the GitCommandError exception if the
binary exited with that return code, otherwise it suppresses
the exception. The comments state that return code 128
is used if there was a connection error, so it makes sense
that we'd raise an exception then. However, 128 is also
returned if you ask for a rev-list for a ref that does
not exist locally [2], which we legitimately do in zuul (at least
in the tests), but because of that added call, zuul
acts as if there was a connection error. That shouldn't
happen.

I can think of a few options to fix this:

1) Fix zuul so that we handle GitCommandError when we're
checking out refs. There's a review open [3] that already
fixes the tests, and it seems that we already handle
GitCommandError in the main code when we know it
could happen.

2) Fix finalize_process somehow to only re-raise the
exception when git is dealing with a remote source - 
this seems very tricky as we'd need to inspect the original
command used to spawn the process...

3) Deal with the GitCommandError in GitPython, handling
GitCommandError when we know we're not dealing with a
remote source, or it doesn't make sense to raise a connection
related error (like, when you're checking for local untracked files).

4) Do 1 and 3.

What looks best? I'm keen to get this fixed :)

Cheers,
Mike

[1] https://github.com/gitpython-developers/GitPython/commit/ff13922f
[2] :
mikeh at TARDIS:~/code/zuul$ git rev-list refs/i/do/not/exist
fatal: ambiguous argument 'refs/i/do/not/exist': unknown revision or path not in the working tree.
Use '--' to separate paths from revisions, like this:
'git <command> [<revision>...] -- [<file>...]'
mikeh at TARDIS:~/code/zuul$ echo $?
128
[3] https://review.openstack.org/#/c/136281/