Question: What's the proper way to install "siblings" [1] in devstack based zuul v3 jobs for projects that also require the siblings via requirements.txt? Background: Following the zuul v3 migration guide for "sibling requirements" [1] works fine for non-devstack based jobs. However, jobs that use devstack must take other measures to install those siblings in their playbooks. Based on what I see projects like oslo.messaging doing for cross testing, they are using the PROJECTS env var to specify the siblings in their playbook (example [2]). This approach may work if those siblings are not in requirements.txt, but for projects that also require the siblings at runtime (in requirements.txt) it appears the version from the requirements.txt is used rather than the sibling's source. For example the changes in [3][4]. Thanks [1] https://docs.openstack.org/infra/manual/zuulv3.html#installation-of-sibling-requirements [2] https://github.com/openstack/oslo.messaging/blob/master/playbooks/oslo.messaging-telemetry-dsvm-integration-amqp1/run.yaml#L37 [3] https://review.openstack.org/#/c/638099 [4] http://logs.openstack.org/99/638099/6/check/tricircle-functional/0b34687/logs/devstacklog.txt.gz#_2019-02-21_14_57_44_553