# neutron-db-manage upgrade liberty
/usr/lib/python2.7/dist-packages/alembic/util/messaging.py:69: UserWarning: Revision havana referenced from havana -> 1cbdb560f806 (head), empty message is not present
  warnings.warn(msg)
Traceback (most recent call last):
  File "/usr/bin/neutron-db-manage", line 10, in <module>
    sys.exit(main())
  File "/usr/lib/python2.7/dist-packages/neutron/db/migration/cli.py", line 570, in main
    CONF.command.func(config, CONF.command.name)
  File "/usr/lib/python2.7/dist-packages/neutron/db/migration/cli.py", line 189, in do_upgrade
    EXPAND_BRANCH)
  File "/usr/lib/python2.7/dist-packages/neutron/db/migration/cli.py", line 141, in _find_milestone_revisions
    for m in script.walk_revisions(base='base', head='heads')
  File "/usr/lib/python2.7/dist-packages/alembic/script/base.py", line 181, in walk_revisions
    head, base, inclusive=True, assert_relative_length=False):
  File "/usr/lib/python2.7/dist-packages/alembic/script/revision.py", line 610, in _iterate_revisions
    requested_lowers = self.get_revisions(lower)
  File "/usr/lib/python2.7/dist-packages/alembic/script/revision.py", line 301, in get_revisions
    resolved_id, branch_label = self._resolve_revision_number(id_)
  File "/usr/lib/python2.7/dist-packages/alembic/script/revision.py", line 423, in _resolve_revision_number
    self._revision_map
  File "/usr/lib/python2.7/dist-packages/alembic/util/langhelpers.py", line 241, in __get__
    obj.__dict__[self.__name__] = result = self.fget(obj)
  File "/usr/lib/python2.7/dist-packages/alembic/script/revision.py", line 151, in _revision_map
    down_revision = map_[downrev]
KeyError: 'havana'