bzr selftest error after clean install on Mac OS X 10.5 (Leopard)

My primary machine is my laptop, a MacBook. Recently, after installing Bazaar 1.16 using the Mac OS X installer, I ran `bzr selftest' and got a bunch of errors.

Since I have updated Python on that machine, and played around with many Bazaar plugins, I decided to try it on my desktop where I haven't altered much of anything. The desktop is an iMac running the same version of OS X as the laptop.

After running the Bazaar 1.16.1 installer on my desktop, I opened a Terminal and tried the selftest, with the following results:

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Tonys-iMac:~ tony$ bzr selftest --verbose
bzr: ERROR: exceptions.AttributeError: 'module' object has no attribute 'TransportTestProviderAdapter'

Traceback (most recent call last):
  File "/Library/Python/2.5/site-packages/bzrlib/commands.py", line 729, in exception_to_return_code
    return the_callable(*args, **kwargs)
  File "/Library/Python/2.5/site-packages/bzrlib/commands.py", line 924, in run_bzr
    ret = run(*run_argv)
  File "/Library/Python/2.5/site-packages/bzrlib/commands.py", line 560, in run_argv_aliases
    return self.run(**all_cmd_args)
  File "/Library/Python/2.5/site-packages/bzrlib/builtins.py", line 3359, in run
    result = selftest(**selftest_kwargs)
  File "/Library/Python/2.5/site-packages/bzrlib/tests/__init__.py", line 3146, in selftest
    suite = test_suite(keep_only, starting_with)
  File "/Library/Python/2.5/site-packages/bzrlib/tests/__init__.py", line 3584, in test_suite
    plugin_suite = plugin.load_plugin_tests(loader)
  File "/Library/Python/2.5/site-packages/bzrlib/plugin.py", line 383, in load_plugin_tests
    return loader.loadTestsFromModule(self.module)
  File "/Library/Python/2.5/site-packages/bzrlib/tests/TestUtil.py", line 129, in loadTestsFromModule
    return load_tests(basic_tests, module, self)
  File "/Library/Python/2.5/site-packages/bzrlib/plugins/upload/__init__.py", line 421, in load_tests
    ["%s.%s" % (__name__, tmn) for tmn in testmod_names]))
  File "/Library/Python/2.5/site-packages/bzrlib/tests/TestUtil.py", line 92, in loadTestsFromModuleNames
    result.addTests(self.loadTestsFromModuleName(name))
  File "/Library/Python/2.5/site-packages/bzrlib/tests/TestUtil.py", line 99, in loadTestsFromModuleName
    result.addTests(self.loadTestsFromModule(module))
  File "/Library/Python/2.5/site-packages/bzrlib/tests/TestUtil.py", line 129, in loadTestsFromModule
    return load_tests(basic_tests, module, self)
  File "/Library/Python/2.5/site-packages/bzrlib/plugins/upload/tests/__init__.py", line 27, in load_tests
    ["%s.%s" % (__name__, tmn) for tmn in testmod_names]))
  File "/Library/Python/2.5/site-packages/bzrlib/tests/TestUtil.py", line 92, in loadTestsFromModuleNames
    result.addTests(self.loadTestsFromModuleName(name))
  File "/Library/Python/2.5/site-packages/bzrlib/tests/TestUtil.py", line 97, in loadTestsFromModuleName
    module = _load_module_by_name(name)
  File "/Library/Python/2.5/site-packages/bzrlib/tests/TestUtil.py", line 166, in _load_module_by_name
    module = __import__(mod_name)
  File "/Library/Python/2.5/site-packages/bzrlib/plugins/upload/tests/test_upload.py", line 45, in <module>
    test_transport_implementations.TransportTestProviderAdapter):
AttributeError: 'module' object has no attribute 'TransportTestProviderAdapter'

bzr 1.16.1 on python 2.5.1 (darwin)
arguments: ['/usr/local/bin/bzr', 'selftest', '--verbose']
encoding: 'UTF-8', fsenc: 'utf-8', lang: 'en_US.UTF-8'
plugins:
  bzrtools /Library/Python/2.5/site-packages/bzrlib/plugins/bzrtools [1.16]
  email /Library/Python/2.5/site-packages/bzrlib/plugins/email [unknown]
  extmerge /Library/Python/2.5/site-packages/bzrlib/plugins/extmerge [unknown]
  launchpad /Library/Python/2.5/site-packages/bzrlib/plugins/launchpad [1.16.1]
  loom /Library/Python/2.5/site-packages/bzrlib/plugins/loom [1.4dev]
  netrc_credential_store /Library/Python/2.5/site-packages/bzrlib/plugins/netrc_credential_store [1.16.1]
  qbzr /Library/Python/2.5/site-packages/bzrlib/plugins/qbzr [0.11]
  rebase /Library/Python/2.5/site-packages/bzrlib/plugins/rebase [0.5.1]
  search /Library/Python/2.5/site-packages/bzrlib/plugins/search [1.7dev]
  svn /Library/Python/2.5/site-packages/bzrlib/plugins/svn [0.6.2]
  upload /Library/Python/2.5/site-packages/bzrlib/plugins/upload [0.1.1]
*** Bazaar has encountered an internal error.
    Please report a bug at https://bugs.launchpad.net/bzr/+filebug
    including this traceback, and a description of what you
    were doing when the error occurred.

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I have two questions:

1. Anything I can do to fix this, or is this one for the devs? (I don't know Python, sorry!)
2. I don't know whether it's safe to use Bazaar on my repositories right now…is this error trivial? Or potentially dangerous?

Thanks.