bzr puke on branch

gistfile1.txt

[cf322@vm-dplprdbzr-01 ~]$ echo "Branching from $SRCBRANCH to $DSTBRANCH."
Branching from utilities to utilities-sbx.

[cf322@vm-dplprdbzr-01 ~]$ bzr  branch bzr+ssh://dplbzr.web.yale.internal/bzr/drupal/${SRCBRANCH} bzr+ssh://dplbzr.web.yale.internal/bzr/drupal/${DSTBRANCH}
bzr: ERROR: exceptions.AttributeError: ImportError instance has no attribute 'message'

Traceback (most recent call last):
  File "/usr/lib/python2.4/site-packages/bzrlib/commands.py", line 835, in exception_to_return_code
    return the_callable(*args, **kwargs)
  File "/usr/lib/python2.4/site-packages/bzrlib/commands.py", line 1030, in run_bzr
    ret = run(*run_argv)
  File "/usr/lib/python2.4/site-packages/bzrlib/commands.py", line 647, in run_argv_aliases
    return self.run(**all_cmd_args)
  File "/usr/lib/python2.4/site-packages/bzrlib/builtins.py", line 1203, in run
    accelerator_tree, br_from = bzrdir.BzrDir.open_tree_or_branch(
  File "/usr/lib/python2.4/site-packages/bzrlib/bzrdir.py", line 951, in open_tree_or_branch
    bzrdir = klass.open(location)
  File "/usr/lib/python2.4/site-packages/bzrlib/bzrdir.py", line 835, in open
    t = get_transport(base, possible_transports=possible_transports)
  File "/usr/lib/python2.4/site-packages/bzrlib/lazy_import.py", line 125, in __call__
    return obj(*args, **kwargs)
  File "/usr/lib/python2.4/site-packages/bzrlib/transport/__init__.py", line 1587, in get_transport
    transport, last_err = _try_transport_factories(base, factory_list)
  File "/usr/lib/python2.4/site-packages/bzrlib/transport/__init__.py", line 1610, in _try_transport_factories
    return factory.get_obj()(base), None
  File "/usr/lib/python2.4/site-packages/bzrlib/transport/remote.py", line 110, in __init__
    medium, credentials = self._build_medium()
  File "/usr/lib/python2.4/site-packages/bzrlib/transport/remote.py", line 516, in _build_medium
    user = auth.get_user('ssh', self._host, self._port)
  File "/usr/lib/python2.4/site-packages/bzrlib/config.py", line 1156, in get_user
    path=path, realm=realm)
  File "/usr/lib/python2.4/site-packages/bzrlib/config.py", line 1084, in get_credentials
    credentials = credential_store_registry.get_fallback_credentials(
  File "/usr/lib/python2.4/site-packages/bzrlib/config.py", line 1263, in get_fallback_credentials
    cs = self.get_credential_store(name)
  File "/usr/lib/python2.4/site-packages/bzrlib/config.py", line 1244, in get_credential_store
    cs = self.get(encoding)
  File "/usr/lib/python2.4/site-packages/bzrlib/registry.py", line 173, in get
    return self._dict[self._get_key_or_default(key)].get_obj()
  File "/usr/lib/python2.4/site-packages/bzrlib/registry.py", line 61, in get_obj
    self._do_import()
  File "/usr/lib/python2.4/site-packages/bzrlib/registry.py", line 70, in _do_import
    obj = __import__(self._module_name, globals(), locals(), names)
  File "/home/cf322/.bazaar/plugins/svn/auth.py", line 20, in ?
    import subvertpy
  File "/usr/lib/python2.4/site-packages/subvertpy/__init__.py", line 114, in ?
    raise ImportError("Unable to load subvertpy extensions: %s", e.message)
AttributeError: ImportError instance has no attribute 'message'

bzr 1.17 on python 2.4.3 (linux2)
arguments: ['/usr/bin/bzr', 'branch', 'bzr+ssh://dplbzr.web.yale.internal/bzr/drupal/utilities', 'bzr+ssh://dplbzr.web.yale.internal/bzr/drupal/utilities-sbx']
encoding: 'UTF-8', fsenc: 'UTF-8', lang: 'en_US.UTF-8'
plugins:
  launchpad            /usr/lib/python2.4/site-packages/bzrlib/plugins/launchpad [1.17]
  netrc_credential_store /usr/lib/python2.4/site-packages/bzrlib/plugins/netrc_credential_store [1.17]
  svn                  /home/cf322/.bazaar/plugins/svn [1.0.1]
*** 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.