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

Build failed. https://zuul.opendev.org/t/openstack/buildset/0e4a92d4e24e4c74b36d06a8436c0e... - openstack-tox-docs https://zuul.opendev.org/t/openstack/build/ed38982970c14ea9b3bc169c751419b2 : SUCCESS in 4m 45s - openstack-tox-py27 https://zuul.opendev.org/t/openstack/build/1c81e6a464c24966b077cc2931a92efa : SUCCESS in 5m 35s - openstack-tox-py36 https://zuul.opendev.org/t/openstack/build/fa879b5ed11c44138af2cb4d36911b09 : SUCCESS in 4m 27s - openstack-tox-py37 https://zuul.opendev.org/t/openstack/build/6460f34925a74130ac382e53764c9757 : FAILURE in 6m 50s