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

Build failed. https://zuul.opendev.org/t/openstack/buildset/7f9e82be14d640cb93aaddea2cc7b3... - openstack-tox-docs https://zuul.opendev.org/t/openstack/build/5cf1d8f9e84f4b83b81d7fcc693010c6 : SUCCESS in 5m 53s - openstack-tox-py27 https://zuul.opendev.org/t/openstack/build/d4fdb5104c144f58bbe372df11905337 : SUCCESS in 5m 45s - openstack-tox-py36 https://zuul.opendev.org/t/openstack/build/92a288760333414c8638baf1e778d43a : SUCCESS in 4m 54s - openstack-tox-py37 https://zuul.opendev.org/t/openstack/build/9fbcc0cb571843beaa43e1707b0bb482 : FAILURE in 5m 46s