bzr fix-svn-ancestry crash with BzrCheckError

Managed to get the repository confused by not merging properly.
Ran $bzr fix-svn-ancestry svn+ssh:.....

Stack Trace

Fetching other revisions
bzr: ERROR: bzrlib.errors.BzrCheckError: Internal check failed: Cannot add revision(s) to repository: missing chk node(s) for id_to_entry maps

Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/bzrlib/commands.py", line 920, in exception_to_return_code
    return the_callable(*args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/bzrlib/commands.py", line 1131, 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 695, 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/plugins/svn/commands.py", line 363, in run
    new_repo.fetch(old_repo)
  File "/usr/lib/python2.7/dist-packages/bzrlib/vf_repository.py", line 1267, in fetch
    find_ghosts=find_ghosts, fetch_spec=fetch_spec)
  File "/usr/lib/python2.7/dist-packages/bzrlib/decorators.py", line 218, in write_locked
    result = unbound(self, *args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/bzrlib/vf_repository.py", line 2584, in fetch
    find_ghosts=find_ghosts)
  File "/usr/lib/python2.7/dist-packages/bzrlib/fetch.py", line 77, in __init__
    self.__fetch()
  File "/usr/lib/python2.7/dist-packages/bzrlib/fetch.py", line 104, in __fetch
    self._fetch_everything_for_search(search_result)
  File "/usr/lib/python2.7/dist-packages/bzrlib/fetch.py", line 132, in _fetch_everything_for_search
    stream, from_format, [])
  File "/usr/lib/python2.7/dist-packages/bzrlib/vf_repository.py", line 2050, in insert_stream
    hint = self.target_repo.commit_write_group()
  File "/usr/lib/python2.7/dist-packages/bzrlib/repository.py", line 633, in commit_write_group
    result = self._commit_write_group()
  File "/usr/lib/python2.7/dist-packages/bzrlib/repofmt/pack_repo.py", line 1727, in _commit_write_group
    hint = self._pack_collection._commit_write_group()
  File "/usr/lib/python2.7/dist-packages/bzrlib/repofmt/pack_repo.py", line 1607, in _commit_write_group
    "Cannot add revision(s) to repository: " + problems_summary)
BzrCheckError: Internal check failed: Cannot add revision(s) to repository: missing chk node(s) for id_to_entry maps

bzr 2.5.1 on python 2.7.3 (Linux-3.2.0-23-generic-i686-with-LinuxMint-13-maya)
arguments: ['/usr/bin/bzr', 'fix-svn-ancestry',
    'svn+ssh://<email address hidden>/svn/dang/myWriting/lyxThesis']
plugins: bash_completion[2.5.1], changelog_merge[2.5.1], launchpad[2.5.1],
    netrc_credential_store[2.5.1], news_merge[2.5.1], po_merge[2.5.1],
    rewrite[0.6.3], svn[1.2.1], weave_fmt[2.5.1]
encoding: 'utf-8', fsenc: 'UTF-8', lang: 'en_GB.UTF-8'