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

Build failed. https://zuul.opendev.org/t/openstack/buildset/b6ae6b731cc84ed7bbbcaee1793346... - openstack-tox-docs https://zuul.opendev.org/t/openstack/build/78c2febf14ed44b5872d7f66b8268e36 : SUCCESS in 4m 57s - openstack-tox-py27 https://zuul.opendev.org/t/openstack/build/2710a7b278764599b46724924c7c279d : SUCCESS in 4m 30s - openstack-tox-py36 https://zuul.opendev.org/t/openstack/build/f19bf13923d84398ba42be59e0d7ab17 : FAILURE in 5m 53s - openstack-tox-py37 https://zuul.opendev.org/t/openstack/build/4c6fb29218634f09b8a704d24790a9ee : FAILURE in 7m 31s