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

Build failed. https://zuul.opendev.org/t/openstack/buildset/441d69ece3e34932b0fa57f5a07964... - openstack-tox-docs https://zuul.opendev.org/t/openstack/build/591b62281ff944dbb3bd17f1ee3447f3 : SUCCESS in 9m 21s - openstack-tox-py27 https://zuul.opendev.org/t/openstack/build/68850f0cc0774e958f949ffaf4f16ec5 : RETRY_LIMIT in 3m 17s - openstack-tox-py36 https://zuul.opendev.org/t/openstack/build/84fc1213ba2f4e7e9bed61073e825c60 : SUCCESS in 14m 33s - openstack-tox-py37 https://zuul.opendev.org/t/openstack/build/8513662dfa8648a28f52c786dc31b21b : SUCCESS in 12m 20s