Interesting, Martin.  Yeah, I think what you encountered is a case of a different bug.  The original traceback for that test that seemed related to the codehosting test failure was this:

Error in test lp.translations.tests.test_rosetta_branches_script.TestRosettaBranchesScript.test_rosetta_branches_script_oops
Traceback (most recent call last):
_StringException: librarian-log: {{{
2011-11-15 19:40:49+0530 [-] Log opened.
2011-11-15 19:40:49+0530 [-] twistd 11.1.0pre1 (/usr/bin/python2.6 2.6.5) starting up.
2011-11-15 19:40:49+0530 [-] reactor class: twisted.internet.pollreactor.PollReactor.
2011-11-15 19:40:49+0530 [-] FileUploadFactory starting on 35368
2011-11-15 19:40:49+0530 [-] Starting factory <canonical.librarian.libraryprotocol.FileUploadFactory instance at 0x37f6cf8>
2011-11-15 19:40:49+0530 [-] Site starting on 39164
2011-11-15 19:40:49+0530 [-] Starting factory <twisted.web.server.Site instance at 0x3757b00>
2011-11-15 19:40:49+0530 [-] FileUploadFactory starting on 57170
2011-11-15 19:40:49+0530 [-] Starting factory <canonical.librarian.libraryprotocol.FileUploadFactory instance at 0x37575f0>
2011-11-15 19:40:49+0530 [-] Site starting on 49954
2011-11-15 19:40:49+0530 [-] Starting factory <twisted.web.server.Site instance at 0x3757a70>
2011-11-15 19:40:49+0530 [-] Not using upstream librarian
2011-11-15 19:40:49+0530 [-] daemon ready!
}}}
Traceback (most recent call last):
  File "/srv/buildbot/slaves/launchpad/lucid-devel/build/lib/lp/translations/tests/test_rosetta_branches_script.py", line 87, in test_rosetta_branches_script_oops
    branch = self._setup_series_branch(pot_path)
  File "/srv/buildbot/slaves/launchpad/lucid-devel/build/lib/lp/translations/tests/test_rosetta_branches_script.py", line 49, in _setup_series_branch
    branch, tree = self.create_branch_and_tree()
  File "/srv/buildbot/slaves/launchpad/lucid-devel/build/lib/lp/testing/__init__.py", line 675, in create_branch_and_tree
    bzr_branch = self.createBranchAtURL(branch_url, format=format)
  File "/srv/buildbot/slaves/launchpad/lucid-devel/build/lib/lp/testing/__init__.py", line 654, in createBranchAtURL
    branch_url, format=format)
  File "/srv/buildbot/slaves/launchpad/lucid-devel/build/orig_sourcecode/eggs/bzr-2.5.0dev2_r6152-py2.6-linux-x86_64.egg/bzrlib/bzrdir.py", line 581, in create_branch_convenience
    bzrdir = BzrDir.create(base, format, possible_transports)
  File "/srv/buildbot/slaves/launchpad/lucid-devel/build/orig_sourcecode/eggs/bzr-2.5.0dev2_r6152-py2.6-linux-x86_64.egg/bzrlib/bzrdir.py", line 1039, in create
    return format.initialize_on_transport(t)
  File "/srv/buildbot/slaves/launchpad/lucid-devel/build/orig_sourcecode/eggs/bzr-2.5.0dev2_r6152-py2.6-linux-x86_64.egg/bzrlib/bzrdir.py", line 1430, in initialize_on_transport
    return self._initialize_on_transport_vfs(transport)
  File "/srv/buildbot/slaves/launchpad/lucid-devel/build/orig_sourcecode/eggs/bzr-2.5.0dev2_r6152-py2.6-linux-x86_64.egg/bzrlib/bzrdir.py", line 1569, in _initialize_on_transport_vfs
    control_files.lock_write()
  File "/srv/buildbot/slaves/launchpad/lucid-devel/build/orig_sourcecode/eggs/bzr-2.5.0dev2_r6152-py2.6-linux-x86_64.egg/bzrlib/lockable_files.py", line 162, in lock_write
    token_from_lock = self._lock.lock_write(token=token)
  File "/srv/buildbot/slaves/launchpad/lucid-devel/build/orig_sourcecode/eggs/bzr-2.5.0dev2_r6152-py2.6-linux-x86_64.egg/bzrlib/lockdir.py", line 671, in lock_write
    return self.wait_lock()
  File "/srv/buildbot/slaves/launchpad/lucid-devel/build/orig_sourcecode/eggs/bzr-2.5.0dev2_r6152-py2.6-linux-x86_64.egg/bzrlib/lockdir.py", line 601, in wait_lock
    return self.attempt_lock()
  File "/srv/buildbot/slaves/launchpad/lucid-devel/build/orig_sourcecode/eggs/bzr-2.5.0dev2_r6152-py2.6-linux-x86_64.egg/bzrlib/lockdir.py", line 554, in attempt_lock
    hook(hook_result)
  File "/srv/buildbot/slaves/launchpad/lucid-devel/build/orig_sourcecode/eggs/bzr-2.5.0dev2_r6152-py2.6-linux-x86_64.egg/bzrlib/tests/__init__.py", line 1168, in _lock_acquired
    self._lock_actions.append(('acquired', result))
AttributeError: 'TestPullerMasterIntegration' object has no attribute '_lock_actions'