[Openstack-stable-maint] Stable check of openstack/tooz for ref refs/heads/stable/train failed

Build failed. https://zuul.opendev.org/t/openstack/buildset/b6159981bc2c487f8835ab504f499b... - openstack-tox-docs https://zuul.opendev.org/t/openstack/build/2fb6f7cc46f34d4dae639c79b3b8b76a : SUCCESS in 4m 45s - openstack-tox-py27 https://zuul.opendev.org/t/openstack/build/c66dc4beca3b4538b865c265c65cc3d6 : SUCCESS in 5m 14s - openstack-tox-py36 https://zuul.opendev.org/t/openstack/build/f9591a26d7084126b49dfacaf06d78f2 : SUCCESS in 4m 28s - openstack-tox-py37 https://zuul.opendev.org/t/openstack/build/1897cc613ce84dd7889a4256e106a77b : FAILURE in 4m 52s