Comment 6 for bug 1830770

Following the same process as above, pointing at ocata-proposed, I see the the python-nova upgrade successfully pull in the oslo.middleware package as well:

root@test:~# apt-cache policy python-nova
python-nova:
  Installed: 2:15.1.5-0ubuntu1~cloud6
  Candidate: 2:15.1.5-0ubuntu1~cloud6
  Version table:
 *** 2:15.1.5-0ubuntu1~cloud6 500
        500 http://ubuntu-cloud.archive.canonical.com/ubuntu xenial-proposed/ocata/main amd64 Packages
        100 /var/lib/dpkg/status
     2:13.1.4-0ubuntu4.5 500
        500 http://archive.ubuntu.com/ubuntu xenial-updates/main amd64 Packages
        500 http://security.ubuntu.com/ubuntu xenial-security/main amd64 Packages
     2:13.0.0-0ubuntu2 500
        500 http://archive.ubuntu.com/ubuntu xenial/main amd64 Packages
root@test:~# apt-cache policy python-oslo.middleware
python-oslo.middleware:
  Installed: 3.23.1-0ubuntu1.1~cloud0
  Candidate: 3.23.1-0ubuntu1.1~cloud0
  Version table:
 *** 3.23.1-0ubuntu1.1~cloud0 500
        500 http://ubuntu-cloud.archive.canonical.com/ubuntu xenial-proposed/ocata/main amd64 Packages
        100 /var/lib/dpkg/status
     3.8.0-2ubuntu1 500
        500 http://archive.ubuntu.com/ubuntu xenial-updates/main amd64 Packages
        500 http://security.ubuntu.com/ubuntu xenial-security/main amd64 Packages
     3.8.0-2 500
        500 http://archive.ubuntu.com/ubuntu xenial/main amd64 Packages