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

Build failed. https://zuul.opendev.org/t/openstack/buildset/b4cba9f8dc67407eafa54f129d9bc2... - openstack-tox-docs https://zuul.opendev.org/t/openstack/build/8dd983830c614829b3b2eba2ba6b9f9b : RETRY_LIMIT in 2s - openstack-tox-py27 https://zuul.opendev.org/t/openstack/build/e5e73f7ee4774ed88deadbf6565c70ba : RETRY_LIMIT in 2s - openstack-tox-py36 https://zuul.opendev.org/t/openstack/build/f9f114d505a44d79af4ca310772ec572 : SUCCESS in 4m 28s - openstack-tox-py37 https://zuul.opendev.org/t/openstack/build/06cf75b5c5124aebaf7b707dc25f4210 : SUCCESS in 3m 38s