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

Build failed. https://zuul.opendev.org/t/openstack/buildset/a8f0c723ddc74b97b7c47627014bf6... - openstack-tox-docs https://zuul.opendev.org/t/openstack/build/464b3af3a49644b188a043c23cb2e772 : SUCCESS in 5m 48s - openstack-tox-py27 https://zuul.opendev.org/t/openstack/build/b6f1accba35e47c2af4216f72baf54bf : SUCCESS in 4m 21s - openstack-tox-py36 https://zuul.opendev.org/t/openstack/build/ddcc32fdb1ba408ca27bf92f31b284e8 : FAILURE in 6m 53s - openstack-tox-py37 https://zuul.opendev.org/t/openstack/build/6f0611e3d9ad48ce8b89a55d533d8261 : SUCCESS in 4m 23s