crashes when cloning local git repository with tags pointing at Tree objects

[Andrew Cowie]

Attempting to run the command

    $ bzr branch ~/path/to/git/checkout target

Bazaar crashed with

    AttributeError: 'Tree' object has no attribute 'encoding'

So, as requested, the traceback:

    $ cat ~/.bzr.log
...

Thu 2011-09-29 01:45:00 +0000
0.044 bazaar version: 2.4.1
0.044 bzr arguments: [u'init-repo', u'.']
0.066 looking for plugins in /home/andrew/.bazaar/plugins
0.066 looking for plugins in /usr/lib/pymodules/python2.6/bzrlib/plugins
0.083 looking for plugins in /usr/lib/python2.6/dist-packages/bzrlib/plugins
0.092 encoding stdout as sys.stdout encoding 'UTF-8'
0.121 creating repository in file:///home/andrew/tmp/.bzr/.
0.145 Transferred: 0kB (0.0kB/s r:0kB w:0kB)
0.145 return code 0

Thu 2011-09-29 01:45:18 +0000
0.041 bazaar version: 2.4.1
0.042 bzr arguments: [u'branch', u'/home/andrew/torvalds/linux', u'upstream']
0.064 looking for plugins in /home/andrew/.bazaar/plugins
0.064 looking for plugins in /usr/lib/pymodules/python2.6/bzrlib/plugins
0.081 looking for plugins in /usr/lib/python2.6/dist-packages/bzrlib/plugins
0.094 encoding stdout as sys.stdout encoding 'UTF-8'
1.232 Transferred: 0kB (0.0kB/s r:0kB w:0kB)
1.235 Traceback (most recent call last):
  File "/usr/lib/pymodules/python2.6/bzrlib/commands.py", line 946, in exception_to_return_code
    return the_callable(*args, **kwargs)
  File "/usr/lib/pymodules/python2.6/bzrlib/commands.py", line 1150, in run_bzr
    ret = run(*run_argv)
  File "/usr/lib/pymodules/python2.6/bzrlib/commands.py", line 699, in run_argv_aliases
    return self.run(**all_cmd_args)
  File "/usr/lib/pymodules/python2.6/bzrlib/commands.py", line 721, in run
    return self._operation.run_simple(*args, **kwargs)
  File "/usr/lib/pymodules/python2.6/bzrlib/cleanup.py", line 135, in run_simple
    self.cleanups, self.func, *args, **kwargs)
  File "/usr/lib/pymodules/python2.6/bzrlib/cleanup.py", line 165, in _do_with_cleanups
    result = func(*args, **kwargs)
  File "/usr/lib/pymodules/python2.6/bzrlib/builtins.py", line 1307, in run
    source_branch=br_from)
  File "/usr/lib/python2.6/dist-packages/bzrlib/plugins/git/dir.py", line 169, in sprout
    mapping=source_branch.mapping)
  File "/usr/lib/python2.6/dist-packages/bzrlib/plugins/git/fetch.py", line 668, in fetch_objects
    wants = determine_wants(remote_refs)
  File "/usr/lib/python2.6/dist-packages/bzrlib/plugins/git/fetch.py", line 507, in determine_wants
    return list(potential - self._target_has_shas(potential))
  File "/usr/lib/python2.6/dist-packages/bzrlib/plugins/git/fetch.py", line 529, in _target_has_shas
    revids = [self.source.lookup_foreign_revision_id(sha) for sha in shas]
  File "/usr/lib/python2.6/dist-packages/bzrlib/plugins/git/repository.py", line 313, in lookup_foreign_revision_id
    mapping.revision_id_foreign_to_bzr)
  File "/usr/lib/python2.6/dist-packages/bzrlib/plugins/git/mapping.py", line 328, in import_commit
    if commit.encoding is not None:
AttributeError: 'Tree' object has no attribute 'encoding'

1.236 couldn't find apport bug-reporting library: No module named apport
1.268 return code 4
    $

AfC

[Andrew Cowie (afcowie)]

Sorry, further context: this is on a Lucid server running the Bazaar PPA. As branching from a [local] Git repo appears to work fine on my Natty laptop, I can only assume there is a missing dependency. This system pristine, other than

    # apt-get install --no-install-recommends git-core
    # apt-get install --no-install-recommends bzr
    # apt-get install bzr-git

AfC

[Martin Pool (mbp)]

I don't think this is actually a version mismatch (although that's often the cause of attributeerrors) - it looks like there is a git hash pointing to a tree when it's expected to point to a commit.

[Martin Pool (mbp)]

afc can reproduce this in ppa:bzr/daily, I'm just going to see if i can too.

[Martin Pool (mbp)]

<AfC> poolie: :
 {'rev': <Revision id git-v1:c39ae07f393806ccf406ef966e9a15afc43cc36a>, 'self': <bzrlib.plugins.git.mapping.BzrGitMappingv1 object at 0x1699450>, 'commit': <Tree c39ae07f393806ccf406ef966e9a15afc43cc36a>, 'decode_using_encoding': <function decode_using_encoding at 0x33167d0>, 'lookup_parent_revid': <bound method type.revision_id_foreign_to_bzr of <class 'bzrlib.plugins.git.mapping.BzrGitMappingv1'>>}
<poolie> ok that's useful
<AfC> gesundheit
<poolie> and try 'up' 'p locals()' again
<AfC> ok
 > /usr/lib/python2.6/dist-packages/bzrlib/plugins/git/repository.py(332)lookup_foreign_revision_id()
<AfC> -> mapping.revision_id_foreign_to_bzr)
<AfC> {'foreign_revid': '5dc01c595e6c6ec9ccda4f6f69c131c0dd945f8c', 'commit': <Tree c39ae07f393806ccf406ef966e9a15afc43cc36a>, 'self': LocalGitRepository('file:///home/andrew/torvalds/linux/'), 'mapping': <bzrlib.plugins.git.mapping.BzrGitMappingv1 object at 0x1699450>}

[Martin Pool (mbp)]

(I'll investigate, but jelmer or someone else, feel free to steal it.)

I suspect this is because there's a tag pointing directly to a tree, not to a revision, and bzr-git can't import it. I think this is unusual but permitted in git.

And indeed there is

(Pdb) [(k,v) for (k,v) in refs.items() if v.startswith('5dc')]
[('refs/tags/v2.6.11-tree', '5dc01c595e6c6ec9ccda4f6f69c131c0dd945f8c'), ('refs/tags/v2.6.11', '5dc01c595e6c6ec9ccda4f6f69c131c0dd945f8c')]

One approach for this would be to let lookup_foreign_revision_id to be able to return None in the case that the object passed in is not actually a revision, and then just not to map them across.

[Martin Pool (mbp)]

as a workaround,

  git tag -d v2.6.11
  git tag -d v2.6.11-tree

will let bzr branch this repository it (or at least it gets a lot further along)

[Andrew Cowie (afcowie)]

Lovely. Will this fix be available in ppa:bzr/daily automatically?

AfC

[Andrew Cowie (afcowie)]

On Thu, 2011-09-29 at 05:03 +0000, Martin Pool wrote:
> as a workaround,
>
> git tag -d v2.6.11
> git tag -d v2.6.11-tree
>
> will let bzr branch this repository it (or at least it gets a lot
> further along)

Did your branch ever finish, Martin? Mine is getting ... stuck ... at
about 100k revisions.

AfC

[Martin Pool (mbp)]

> Did your branch ever finish, Martin? Mine is getting ... stuck ... at
> about 100k revisions.

I think I rebooted my laptop, thereby killing it. If it gets stuck,
please file a separate bug with a traceback.