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

Build failed. https://zuul.opendev.org/t/openstack/buildset/4cb8b65eac0f46e1a5cd2d994bdaab... - openstack-tox-docs https://zuul.opendev.org/t/openstack/build/3b45f4e9f7ef4827a7059a30b1881964 : SUCCESS in 5m 20s - openstack-tox-py27 https://zuul.opendev.org/t/openstack/build/b1859e12cffc4e44a93f03af434207b3 : SUCCESS in 4m 47s - openstack-tox-py36 https://zuul.opendev.org/t/openstack/build/ffb374eab2864fab9937b6b42167efa9 : SUCCESS in 4m 51s - openstack-tox-py37 https://zuul.opendev.org/t/openstack/build/439f85d063a0487e8a8e84dcd121ceb4 : FAILURE in 5m 29s