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

Build failed. https://zuul.opendev.org/t/openstack/buildset/a2cb04596c404436b0af541d71825b... - openstack-tox-docs https://zuul.opendev.org/t/openstack/build/c0be480ee6574f2496f7ec28f7fa44bf : SUCCESS in 5m 39s - openstack-tox-py27 https://zuul.opendev.org/t/openstack/build/e3361f772d0c42eca6ec49e67a7978c1 : SUCCESS in 4m 47s - openstack-tox-py36 https://zuul.opendev.org/t/openstack/build/7ce4d1a8b487491cb2bd072ae0b74218 : SUCCESS in 4m 39s - openstack-tox-py37 https://zuul.opendev.org/t/openstack/build/855efa51bb764bc480c579c972b534de : FAILURE in 5m 17s