repo, clone depth=1 and stack overflow

[Felix Hall]

Hi,

We've encountered an error in repo on a few rare occasions when working with clone-depth=1 in our manifest.

I've been able to reproduce it on a certain production git, but have yet to produce a minimal test git with the problem.

A mock-up of the manifest contains the following:

<project clone-depth="1" groups="group" name="platform/some/name" path="some/name" revision="0123456789abcdef0123456789abcdef01234567" upstream="xyz/dev"/>

When performing repo sync here, we get stuck and python bails at stack depth 1000.

Exception RuntimeError: RuntimeError('maximum recursion depth exceeded',) in <module 'threading' from '/usr/lib/python2.7/threading.pyc'> ignored

Exception in thread Thread-120:

Traceback (most recent call last):

  File "/usr/lib/python2.7/threading.py", line 551, in __bootstrap_inner

    self.run()

  File "/usr/lib/python2.7/threading.py", line 504, in run

    self.__target(*self.__args, **self.__kwargs)

  File "/home/myname/somedir/.repo/repo/subcmds/sync.py", line 234, in _FetchProjectList

    success = self._FetchHelper(opt, project, *args, **kwargs)

  File "/home/myname/somedir/.repo/repo/subcmds/sync.py", line 275, in _FetchHelper

    no_tags=opt.no_tags, archive=self.manifest.IsArchive)

  File "/home/myname/somedir/.repo/repo/project.py", line 1114, in Sync_NetworkHalf

    self._InitMRef()

  File "/home/myname/somedir/.repo/repo/project.py", line 2148, in _InitMRef

    self._InitAnyMRef(R_M + self.manifest.branch)

  File "/home/myname/somedir/.repo/repo/project.py", line 2160, in _InitAnyMRef

    self.bare_git.UpdateRef(ref, dst, message = msg, detach = True)

  File "/home/myname/somedir/.repo/repo/project.py", line 2406, in UpdateRef

    self.update_ref(*cmdv)

  File "/home/myname/somedir/.repo/repo/project.py", line 2483, in runner

    p.stderr))

GitError: platform/some/name update-ref: fatal: 0123456789abcdef0123456789abcdef01234567^0: not a valid SHA1

Stepping it through, I've reached the _RemoteFetch() in project.py, in the end of which we're doing the following:

    if is_sha1 and current_branch_only and self.upstream:

      # We just synced the upstream given branch; verify we

      # got what we wanted, else trigger a second run of all

      # refs.

      if not self._CheckForSha1():

        return self._RemoteFetch(name=name, current_branch_only=False,

                                 initial=False, quiet=quiet, alt_dir=alt_dir)

However, _CheckForSha1() checks whether the sha1 is correct by trying to find its parent through "git-rev-parse --verify 0123456789abcdef0123456789abcdef01234567^0", which 

will fail if the clone-depth is 1. In case of failure, we recurse with the same parameters as last time...

Do we need to add a special case here in case depth=1? Or is there something else that might be fishy?

We don't see this problem often, but it has happened occasionally.

Thankful for any advice on how to proceed!

Regards,

Felix

[Felix Hall]

Version info btw:

repo version v1.12.16

       (from https://gerrit.googlesource.com/git-repo)

repo launcher version 1.21

       (from /usr/bin/repo.vanilla)

git version 1.8.2.2

Python 2.7.3 (default, Feb 27 2014, 19:58:35) 

[GCC 4.6.3]

[Felix Hall]

Should I put this in a new issue, or is there any more info I should add first?

@David, any ideas how to proceed?

Regards,

Felix