Could not find a version that satisfies the requirement packaging>=20.4 (from oslo-utils)

[Lee Yarwood]

Description
===========
openstack-tox-lower-constraints on openstack/nova master & stable/victoria is often failing due to the following error to find a version of the packaging module as required by oslo.utils:

2020-12-07 13:25:45.153758 | ubuntu-focal | ERROR: Could not find a version that satisfies the requirement packaging>=20.4 (from oslo-utils)
2020-12-07 13:25:45.153770 | ubuntu-focal | ERROR: No matching distribution found for packaging>=20.4

The following logstash query finds 11 hits at present:

http://logstash.openstack.org/#dashboard/file/logstash.json?query=message%3A%5C%22No%20matching%20distribution%20found%20for%20packaging%5C%22%20AND%20tags%3A%5C%22console%5C%22

fungi was able to reproduce this and found that Nova's lower-constraints.txt is actually to blame after the following change bumped our oslo.utils requirement to 4.5:

https://review.opendev.org/c/openstack/nova/+/748059

oslo.utils having a lower-constraints.txt packaging requirement of 20.4 while Nova has a lower-constraints.txt packaging requirement of 17.1 creating the conflict. To fix this we need to bump the requirement in Nova to 20.4.

Steps to reproduce
==================

* Use a recent version of pip with the lower-constraints env.

Expected result
===============
Passes

Actual result
=============
Fails

Environment
===========
1. Exact version of OpenStack you are running. See the following
  list for all releases: http://docs.openstack.org/releases/

   master and stable/victoria

2. Which hypervisor did you use?
   (For example: Libvirt + KVM, Libvirt + XEN, Hyper-V, PowerKVM, ...)
   What's the version of that?

   N/A

2. Which storage type did you use?
   (For example: Ceph, LVM, GPFS, ...)
   What's the version of that?

   N/A

3. Which networking type did you use?
   (For example: nova-network, Neutron with OpenVSwitch, ...)

   N/A

Logs & Configs
==============

See above.

[Balazs Gibizer (balazs-gibizer)]

fix proposed to master https://review.opendev.org/c/openstack/nova/+/765824

[Lee Yarwood (lyarwood)]

I totally forgot to highlight that this looks like an issue uncovered by the new resolver in recent versions of pip (20.3.1 in this case).

[melanie witt (melwitt)]

Patch at https://review.opendev.org/c/openstack/nova/+/765749

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/nova 22.1.0 release.

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/nova 23.0.0.0rc1 release candidate.