@Brian, I just start from an empty database.

I try to upgrade empty database to Ocata(neutron-db-manage upgrade ocata), then the alembic_version is Ocata expand. [1]
MariaDB [neutron]> select * from alembic_version;
+--------------+
| version_num  |
+--------------+
| a9c43481023c |
+--------------+
1 row in set (0.00 sec)

Then I upgrade expand branch, it raises an exception here:
# neutron-db-manage upgrade --expand
INFO  [alembic.runtime.migration] Context impl MySQLImpl.
INFO  [alembic.runtime.migration] Will assume non-transactional DDL.
Running upgrade (expand) for neutron ...
INFO  [alembic.runtime.migration] Context impl MySQLImpl.
INFO  [alembic.runtime.migration] Will assume non-transactional DDL.
INFO  [alembic.runtime.migration] Running upgrade kilo -> 30018084ec99
INFO  [alembic.runtime.migration] Running upgrade 30018084ec99 -> 4ffceebfada
INFO  [alembic.runtime.migration] Running upgrade 4ffceebfada -> 5498d17be016
INFO  [alembic.runtime.migration] Running upgrade 5498d17be016 -> 2a16083502f3
INFO  [alembic.runtime.migration] Running upgrade 2a16083502f3 -> 2e5352a0ad4d
INFO  [alembic.runtime.migration] Running upgrade 2e5352a0ad4d -> 11926bcfe72d
INFO  [alembic.runtime.migration] Running upgrade 11926bcfe72d -> 4af11ca47297
INFO  [alembic.runtime.migration] Running upgrade 4af11ca47297 -> 1b294093239c
INFO  [alembic.runtime.migration] Running upgrade 1b294093239c -> 8a6d8bdae39
INFO  [alembic.runtime.migration] Running upgrade 8a6d8bdae39 -> 2b4c2465d44b
INFO  [alembic.runtime.migration] Running upgrade 2b4c2465d44b -> e3278ee65050
INFO  [alembic.runtime.migration] Running upgrade e3278ee65050 -> c6c112992c9
INFO  [alembic.runtime.migration] Running upgrade c6c112992c9 -> 5ffceebfada
INFO  [alembic.runtime.migration] Running upgrade 5ffceebfada -> 4ffceebfcdc
INFO  [alembic.runtime.migration] Running upgrade 4ffceebfcdc -> 7bbb25278f53
INFO  [alembic.runtime.migration] Running upgrade 7bbb25278f53 -> 89ab9a816d70
INFO  [alembic.runtime.migration] Running upgrade 89ab9a816d70 -> c879c5e1ee90
INFO  [alembic.runtime.migration] Running upgrade c879c5e1ee90 -> 8fd3918ef6f4
INFO  [alembic.runtime.migration] Running upgrade 8fd3918ef6f4 -> 4bcd4df1f426
INFO  [alembic.runtime.migration] Running upgrade 4bcd4df1f426 -> b67e765a3524
INFO  [alembic.runtime.migration] Running upgrade a9c43481023c -> 804a3c76314c
INFO  [alembic.runtime.migration] Running upgrade 804a3c76314c -> 2b42d90729da
INFO  [alembic.runtime.migration] Running upgrade 2b42d90729da -> 62c781cb6192
INFO  [alembic.runtime.migration] Running upgrade 62c781cb6192 -> c8c222d42aa9
INFO  [alembic.runtime.migration] Running upgrade c8c222d42aa9 -> 349b6fd605a6
INFO  [alembic.runtime.migration] Running upgrade 349b6fd605a6 -> 7d32f979895f
INFO  [alembic.runtime.migration] Running upgrade 7d32f979895f -> 594422d373ee
INFO  [alembic.runtime.migration] Running upgrade 594422d373ee -> 61663558142c
OK
INFO  [alembic.runtime.migration] Context impl MySQLImpl.
INFO  [alembic.runtime.migration] Will assume non-transactional DDL.
Traceback (most recent call last):
  File "/var/lib/kolla/venv/bin/neutron-db-manage", line 10, in <module>
    sys.exit(main())
  File "/var/lib/kolla/venv/lib/python2.7/site-packages/neutron/db/migration/cli.py", line 653, in main
    return_val |= bool(CONF.command.func(config, CONF.command.name))
  File "/var/lib/kolla/venv/lib/python2.7/site-packages/neutron/db/migration/cli.py", line 172, in do_upgrade
    run_sanity_checks(config, revision)
  File "/var/lib/kolla/venv/lib/python2.7/site-packages/neutron/db/migration/cli.py", line 637, in run_sanity_checks
    script_dir.run_env()
  File "/var/lib/kolla/venv/lib/python2.7/site-packages/alembic/script/base.py", line 427, in run_env
    util.load_python_file(self.dir, 'env.py')
  File "/var/lib/kolla/venv/lib/python2.7/site-packages/alembic/util/pyfiles.py", line 81, in load_python_file
    module = load_module_py(module_id, path)
  File "/var/lib/kolla/venv/lib/python2.7/site-packages/alembic/util/compat.py", line 141, in load_module_py
    mod = imp.load_source(module_id, path, fp)
  File "/var/lib/kolla/venv/lib/python2.7/site-packages/networking_infoblox/neutron/db/migration/alembic_migrations/env.py", line 88, in <module>
    run_migrations_online()
  File "/var/lib/kolla/venv/lib/python2.7/site-packages/networking_infoblox/neutron/db/migration/alembic_migrations/env.py", line 79, in run_migrations_online
    context.run_migrations()
  File "<string>", line 8, in run_migrations
  File "/var/lib/kolla/venv/lib/python2.7/site-packages/alembic/runtime/environment.py", line 836, in run_migrations
    self.get_context().run_migrations(**kw)
  File "/var/lib/kolla/venv/lib/python2.7/site-packages/alembic/runtime/migration.py", line 321, in run_migrations
    for step in self._migrations_fn(heads, self):
  File "/var/lib/kolla/venv/lib/python2.7/site-packages/neutron/db/migration/cli.py", line 628, in check_sanity
    revision, rev, implicit_base=True):
  File "/var/lib/kolla/venv/lib/python2.7/site-packages/alembic/script/revision.py", line 656, in _iterate_revisions
    uppers = util.dedupe_tuple(self.get_revisions(upper))
  File "/var/lib/kolla/venv/lib/python2.7/site-packages/alembic/script/revision.py", line 301, in get_revisions
    resolved_id, branch_label = self._resolve_revision_number(id_)
  File "/var/lib/kolla/venv/lib/python2.7/site-packages/alembic/script/revision.py", line 445, in _resolve_revision_number
    current_head = self.get_current_head(branch_label)
  File "/var/lib/kolla/venv/lib/python2.7/site-packages/alembic/script/revision.py", line 267, in get_current_head
    current_heads = self.filter_for_lineage(current_heads, branch_label)
  File "/var/lib/kolla/venv/lib/python2.7/site-packages/alembic/script/revision.py", line 405, in filter_for_lineage
    tg, shares, include_dependencies=include_dependencies)]
  File "/var/lib/kolla/venv/lib/python2.7/site-packages/alembic/script/revision.py", line 419, in _shares_lineage
    in util.to_tuple(test_against_revs, default=())
  File "/var/lib/kolla/venv/lib/python2.7/site-packages/alembic/script/revision.py", line 362, in _revision_for_ident
    resolved_id)
alembic.script.revision.ResolutionError: No such revision or branch 'expand'

[1]  https://github.com/openstack/neutron/blob/stable/ocata/neutron/db/migration/alembic_migrations/versions/EXPAND_HEAD