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

Build failed. https://zuul.opendev.org/t/openstack/buildset/88da88b7b4f9484cbabf0e877bbdb5... - openstack-tox-docs https://zuul.opendev.org/t/openstack/build/ba1008f6618840c3add776208ada96e0 : SUCCESS in 4m 28s - openstack-tox-py27 https://zuul.opendev.org/t/openstack/build/cf39742f954141f3a1b649969127a2c2 : SUCCESS in 6m 13s - openstack-tox-py36 https://zuul.opendev.org/t/openstack/build/73967edc9add4b36a04b30bb7bca6049 : SUCCESS in 4m 57s - openstack-tox-py37 https://zuul.opendev.org/t/openstack/build/d675338386004d7dab0ad66927afdb8b : FAILURE in 3m 57s