bzr-svn broken by latest upload of python-subvertpy

It appears [1] that bzr-svn has been dropped from ubuntu in saucy.
However if it was installed on a system in raring and upgraded, the user will still have it.

Then, when they try to use 'bzr info', it will fail like below. the simple fix is 'apt-get remove bzr-svn', but I'm not sure that is what is intended.

$ python -c 'from subvertpy.wc import CommittedQueue'
Traceback (most recent call last):
  File "<string>", line 1, in <module>
ImportError: cannot import name CommittedQueue

$ bzr info
bzr: ERROR: exceptions.ImportError: cannot import name CommittedQueue

Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/bzrlib/commands.py", line 930, in exception_to_return_code
    return the_callable(*args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/bzrlib/commands.py", line 1121, in run_bzr
    ret = run(*run_argv)
  File "/usr/lib/python2.7/dist-packages/bzrlib/commands.py", line 673, in run_argv_aliases
    return self.run(**all_cmd_args)
  File "/usr/lib/python2.7/dist-packages/bzrlib/commands.py", line 697, in run
    return self._operation.run_simple(*args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/bzrlib/cleanup.py", line 136, in run_simple
    self.cleanups, self.func, *args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/bzrlib/cleanup.py", line 166, in _do_with_cleanups
    result = func(*args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/bzrlib/commands.py", line 1138, in ignore_pipe
    result = func(*args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/bzrlib/builtins.py", line 1853, in run
    verbose=noise_level, outfile=self.outf)
  File "/usr/lib/python2.7/dist-packages/bzrlib/info.py", line 378, in show_bzrdir_info
    outfile)
  File "/usr/lib/python2.7/dist-packages/bzrlib/info.py", line 394, in show_component_info
    format = describe_format(control, repository, branch, working)
  File "/usr/lib/python2.7/dist-packages/bzrlib/info.py", line 499, in describe_format
    format = controldir.format_registry.make_bzrdir(key)
  File "/usr/lib/python2.7/dist-packages/bzrlib/controldir.py", line 1348, in make_bzrdir
    return self.get(key)()
  File "/usr/lib/python2.7/dist-packages/bzrlib/registry.py", line 177, in get
    return self._dict[self._get_key_or_default(key)].get_obj()
  File "/usr/lib/python2.7/dist-packages/bzrlib/registry.py", line 74, in get_obj
    self._obj = get_named_object(self._module_name, self._member_name)
  File "/usr/lib/python2.7/dist-packages/bzrlib/pyutils.py", line 51, in get_named_object
    obj = __import__(module_name, {}, {}, from_list)
  File "/usr/lib/python2.7/dist-packages/bzrlib/plugins/svn/workingtree.py", line 33, in <module>
    from subvertpy.wc import (
ImportError: cannot import name CommittedQueue

You can report this problem to Bazaar's developers by running
    apport-bug /var/crash/bzr.1000.2013-06-05T15:31.crash
if a bug-reporting window does not automatically appear.

$ apt-cache policy bzr python-subvertpy
bzr:
  Installed: 2.6.0~bzr6574-1ubuntu1
  Candidate: 2.6.0~bzr6574-1ubuntu1
  Version table:
 *** 2.6.0~bzr6574-1ubuntu1 0
        500 http://us.archive.ubuntu.com/ubuntu/ saucy/main amd64 Packages
        100 /var/lib/dpkg/status
python-subvertpy:
  Installed: 0.9.1-2
  Candidate: 0.9.1-2
  Version table:
 *** 0.9.1-2 0
        500 http://us.archive.ubuntu.com/ubuntu/ saucy/universe amd64 Packages
        100 /var/lib/dpkg/status

$ apt-cache policy bzr-svn
bzr-svn:
  Installed: 1.2.1-1
  Candidate: 1.2.1-1
  Version table:
 *** 1.2.1-1 0
        100 /var/lib/dpkg/status

--
[1] https://launchpad.net/ubuntu/+source/bzr-svn

ProblemType: Bug
DistroRelease: Ubuntu 13.04
Package: bzr-svn 1.2.1-1
ProcVersionSignature: User Name 3.8.0-23.34-generic 3.8.11
Uname: Linux 3.8.0-23-generic x86_64
ApportVersion: 2.9.2-0ubuntu8.1
Architecture: amd64
Date: Wed Jun 5 15:42:24 2013
Ec2AMI: ami-0000039e
Ec2AMIManifest: FIXME
Ec2AvailabilityZone: nova
Ec2InstanceType: m1.tiny
Ec2Kernel: aki-0000022a
Ec2Ramdisk: ari-0000022a
MarkForUpload: True
PackageArchitecture: all
ProcEnviron:
 TERM=screen
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: bzr-svn
UpgradeStatus: No upgrade log present (probably fresh install)