Stable branches till stable/rocky is using python
version <py3.6. Tempest test those branch in venv
but Tempest tox use the master upper-constraint[1]
which block installation due to dependencies
require >=py3.6. For exmaple, oslo.concurrency 4.0.0
is not compatible for <py3.6.
As we pin Tempest for EM stable brach, we should be
able to use stable constraint for Tempest installation
as well as while running during run-tempest playbook.
tox.ini is hard coded to use master constraint[1] which force
run-tempest to recreate the tox env and use the master constraint.
Fix for that- https://review.opendev.org/#/c/705870/
Devstack can set stable u-c to use via env var so that
Tempest installation in venv will use stable
branch constraint.
Depends-On: https://review.opendev.org/#/c/706426/
[1] bc9fe8eca8/tox.ini (L14)
Change-Id: I5ab1130582354c33d52afafc9720146e174e40e5
7d43b099c5