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

Build failed. https://zuul.opendev.org/t/openstack/buildset/f20cf0815663493ea150741a140052... - openstack-tox-docs https://zuul.opendev.org/t/openstack/build/43aa21d5b79c4f3aa6a0d7ad38a87c61 : SUCCESS in 6m 15s - openstack-tox-py27 https://zuul.opendev.org/t/openstack/build/21ee911125d340628d5074cc7842eddf : SUCCESS in 5m 25s - openstack-tox-py36 https://zuul.opendev.org/t/openstack/build/fec2d9ea851c4230814842c0bb095e83 : SUCCESS in 6m 06s - openstack-tox-py37 https://zuul.opendev.org/t/openstack/build/3609aea409c1450782ddb2415dc3dbc2 : FAILURE in 8m 43s