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

Build failed. https://zuul.opendev.org/t/openstack/buildset/93b419d5ff344daf8689ae5bb7a791... - openstack-tox-docs https://zuul.opendev.org/t/openstack/build/e7f3cdafb83d408ebef5e6dbac54ab68 : SUCCESS in 4m 43s - openstack-tox-py27 https://zuul.opendev.org/t/openstack/build/714e48032ab14e42b37804682e2c9bc2 : SUCCESS in 4m 50s - openstack-tox-py36 https://zuul.opendev.org/t/openstack/build/7954ae8cdcf94ad29eaad8ede989227c : SUCCESS in 7m 00s - openstack-tox-py37 https://zuul.opendev.org/t/openstack/build/99bcaa161958493fb6c8b7ea0af105d6 : FAILURE in 4m 19s