NoSuchRevision in _iter_inventory_xmls running bzr rebase

Attaching full crash, but when trying to rebase lp:~mordred/drizzle/plugin-base-class-merge onto lp:drizzle/build, I got this:

 Traceback (most recent call last):
   File "/usr/lib/python2.6/dist-packages/bzrlib/commands.py", line 842, in exception_to_return_code
     return the_callable(*args, **kwargs)
   File "/usr/lib/python2.6/dist-packages/bzrlib/commands.py", line 1037, in run_bzr
     ret = run(*run_argv)
   File "/usr/lib/python2.6/dist-packages/bzrlib/commands.py", line 654, in run_argv_aliases
     return self.run(**all_cmd_args)
   File "/usr/lib/python2.6/dist-packages/bzrlib/commands.py", line 1052, in ignore_pipe
     result = func(*args, **kwargs)
   File "/usr/lib/python2.6/dist-packages/bzrlib/plugins/rebase/commands.py", line 206, in run
     workingtree_replay(wt, merge_type=merge_type))
   File "/usr/lib/python2.6/dist-packages/bzrlib/plugins/rebase/rebase.py", line 317, in rebase
     replay_fn(repository, revid, newrevid, newparents)
   File "/usr/lib/python2.6/dist-packages/bzrlib/plugins/rebase/rebase.py", line 506, in replay
     merge_type=merge_type)
   File "/usr/lib/python2.6/dist-packages/bzrlib/plugins/rebase/rebase.py", line 477, in replay_delta_workingtree
     complete_revert(wt, [newparents[0]])
   File "/usr/lib/python2.6/dist-packages/bzrlib/plugins/rebase/rebase.py", line 544, in complete_revert
     newtree = wt.branch.repository.revision_tree(newparents[0])
   File "/usr/lib/python2.6/dist-packages/bzrlib/decorators.py", line 138, in read_locked
     result = unbound(self, *args, **kwargs)
   File "/usr/lib/python2.6/dist-packages/bzrlib/repository.py", line 2568, in revision_tree
     inv = self.get_revision_inventory(revision_id)
   File "/usr/lib/python2.6/dist-packages/bzrlib/decorators.py", line 138, in read_locked
     result = unbound(self, *args, **kwargs)
   File "/usr/lib/python2.6/dist-packages/bzrlib/repository.py", line 2527, in get_revision_inventory
     return self.get_inventory(revision_id)
   File "/usr/lib/python2.6/dist-packages/bzrlib/decorators.py", line 138, in read_locked
     result = unbound(self, *args, **kwargs)
   File "/usr/lib/python2.6/dist-packages/bzrlib/repository.py", line 2357, in get_inventory
     return self.iter_inventories([revision_id]).next()
   File "/usr/lib/python2.6/dist-packages/bzrlib/repository.py", line 2380, in _iter_inventories
     for text, revision_id in inv_xmls:
   File "/usr/lib/python2.6/dist-packages/bzrlib/repository.py", line 2405, in _iter_inventory_xmls
     raise errors.NoSuchRevision(self, record.key)
 NoSuchRevision: KnitPackRepository('file:///home/mordred/src/drizzle/.bzr/repository/') has no revision ('<email address hidden>',)