L3 AttributeError in doc job

e.g http://logs.openstack.org/87/199387/116/check/build-openstack-sphinx-docs/a509328/job-output.txt.gz

2018-07-03 01:03:26.111244 | ubuntu-xenial | Warning, treated as error:
2018-07-03 01:03:26.111548 | ubuntu-xenial | autodoc: failed to import module u'midonet.neutron.db.bgp_db_midonet'; the following exception was raised:
2018-07-03 01:03:26.111691 | ubuntu-xenial | Traceback (most recent call last):
2018-07-03 01:03:26.112024 | ubuntu-xenial | File "/home/zuul/.venv/local/lib/python2.7/site-packages/sphinx/ext/autodoc/importer.py", line 152, in import_module
2018-07-03 01:03:26.112140 | ubuntu-xenial | __import__(modname)
2018-07-03 01:03:26.112514 | ubuntu-xenial | File "/home/zuul/src/git.openstack.org/openstack/networking-midonet/midonet/neutron/db/bgp_db_midonet.py", line 22, in <module>
2018-07-03 01:03:26.112701 | ubuntu-xenial | from neutron_dynamic_routing.db import bgp_db
2018-07-03 01:03:26.113035 | ubuntu-xenial | File "/home/zuul/.venv/local/lib/python2.7/site-packages/neutron_dynamic_routing/db/bgp_db.py", line 21, in <module>
2018-07-03 01:03:26.113165 | ubuntu-xenial | from neutron.db import l3_dvr_db
2018-07-03 01:03:26.113413 | ubuntu-xenial | File "/home/zuul/.venv/local/lib/python2.7/site-packages/neutron/db/l3_dvr_db.py", line 41, in <module>
2018-07-03 01:03:26.113524 | ubuntu-xenial | from neutron.db import l3_db
2018-07-03 01:03:26.113819 | ubuntu-xenial | File "/home/zuul/.venv/local/lib/python2.7/site-packages/neutron/db/l3_db.py", line 51, in <module>
2018-07-03 01:03:26.113955 | ubuntu-xenial | from neutron.extensions import l3
2018-07-03 01:03:26.114260 | ubuntu-xenial | File "/home/zuul/.venv/local/lib/python2.7/site-packages/neutron/extensions/l3.py", line 23, in <module>
2018-07-03 01:03:26.114405 | ubuntu-xenial | from neutron.api.v2 import resource_helper
2018-07-03 01:03:26.114730 | ubuntu-xenial | File "/home/zuul/.venv/local/lib/python2.7/site-packages/neutron/api/v2/resource_helper.py", line 20, in <module>
2018-07-03 01:03:26.114877 | ubuntu-xenial | from neutron.api import extensions
2018-07-03 01:03:26.115169 | ubuntu-xenial | File "/home/zuul/.venv/local/lib/python2.7/site-packages/neutron/api/extensions.py", line 32, in <module>
2018-07-03 01:03:26.115336 | ubuntu-xenial | from neutron.plugins.common import constants as const
2018-07-03 01:03:26.115669 | ubuntu-xenial | File "/home/zuul/.venv/local/lib/python2.7/site-packages/neutron/plugins/common/constants.py", line 28, in <module>
2018-07-03 01:03:26.115768 | ubuntu-xenial | 'router': constants.L3,
2018-07-03 01:03:26.115894 | ubuntu-xenial | AttributeError: 'module' object has no attribute 'L3'