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

Build failed. https://zuul.opendev.org/t/openstack/buildset/1c458156623040fea484d631c799a9... - openstack-tox-docs https://zuul.opendev.org/t/openstack/build/bf3c4449322d4009bec97e0cb997fc3c : SUCCESS in 5m 45s - openstack-tox-py27 https://zuul.opendev.org/t/openstack/build/1cb85ac43c194683b9b10de41069ac62 : FAILURE in 6m 20s - openstack-tox-py36 https://zuul.opendev.org/t/openstack/build/be5bb7f4ffbc4fb5a57a4c8e379d2676 : SUCCESS in 6m 32s - openstack-tox-py37 https://zuul.opendev.org/t/openstack/build/b77ffc69446c48c5818b269488015cc8 : SUCCESS in 7m 10s