Comment 46 for bug 1880959

Also checked the python2.7 package on bionic just in case (unit tests use `six` for compatibility so they work either way):

lxc exec oslop bash
root@oslop:~# cat <<EOF >/etc/apt/sources.list.d/ubuntu-$(lsb_release -cs)-proposed.list
> # Enable Ubuntu proposed archive
> deb http://archive.ubuntu.com/ubuntu/ $(lsb_release -cs)-proposed restricted main multiverse universe
> EOF

root@oslop:/usr/lib/python2.7/dist-packages/oslo_policy# cat /etc/apt/sources.list.d/ubuntu-bionic-proposed.list
# Enable Ubuntu proposed archive
deb http://archive.ubuntu.com/ubuntu/ bionic-proposed restricted main multiverse universe

root@oslop:~# apt update && apt install python-oslo.policy python-oslotest

Setting up python-oslo.config (1:5.2.0-0ubuntu1) ...
update-alternatives: using /usr/bin/python2-oslo-config-generator to provide /usr/bin/oslo-config-generator (oslo-config-generator) in auto mode
Setting up python-oslo.policy (1.33.1-0ubuntu3) ...
update-alternatives: using /usr/bin/python2-oslopolicy-sample-generator to provide /usr/bin/oslopolicy-sample-generator (oslopolicy-sample-generator) in auto mode
update-alternatives: using /usr/bin/python2-oslopolicy-checker to provide /usr/bin/oslopolicy-checker (oslopolicy-checker) in auto mode
update-alternatives: using /usr/bin/python2-oslopolicy-policy-generator to provide /usr/bin/oslopolicy-policy-generator (oslopolicy-policy-generator) in auto mode
update-alternatives: using /usr/bin/python2-oslopolicy-list-redundant to provide /usr/bin/oslopolicy-list-redundant (oslopolicy-list-redundant) in auto mode

root@oslop:/usr/lib/python2.7/dist-packages/oslo_policy# PYTHONPATH=`realpath tests` ; python2 -m unittest tests.test_policy.EnforcerTest.test_load_directory_after_file_update
 WARNING [oslo_policy.policy] Policies [u'foo'] reference a rule that is not defined.
.
----------------------------------------------------------------------
Ran 1 test in 0.122s

OK