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

Build failed.

- openstack-tox-docs https://zuul.opendev.org/t/openstack/build/88b84c747fa542eb9799895a0a9d1213 : SUCCESS in 5m 27s - openstack-tox-py27 https://zuul.opendev.org/t/openstack/build/918edc057e524744b7a58812870b63e0 : FAILURE in 5m 15s - openstack-tox-py36 https://zuul.opendev.org/t/openstack/build/7a63e549c3f843c88e7d980e53a96b84 : FAILURE in 5m 38s - openstack-tox-py37 https://zuul.opendev.org/t/openstack/build/e72ccf2d4ce2443cb056414622f9e4e0 : FAILURE in 6m 48s