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

Build failed. https://zuul.opendev.org/t/openstack/buildset/ff5fdebf7a5344ebbe62db3c5aa722... - openstack-tox-docs https://zuul.opendev.org/t/openstack/build/d18f7bb73f5a42aab57bb29a69542519 : SUCCESS in 5m 01s - openstack-tox-py27 https://zuul.opendev.org/t/openstack/build/505f7a9e342d4e4c8393ba0136c98bf0 : SUCCESS in 6m 37s - openstack-tox-py36 https://zuul.opendev.org/t/openstack/build/863bb2677bae4eaa911c3722c9cb0d91 : FAILURE in 4m 24s - openstack-tox-py37 https://zuul.opendev.org/t/openstack/build/6d46b1ffa1704d348c5e45e0f69dac7d : SUCCESS in 6m 19s