With @iballou’s addition to forklift and a green pipeline, a stable box is now available in forklift with a Katello nightly environment. The box is called centos7-katello-nightly-stable.
This means the most recent working nightly environment will stay available even when the nightly Katello rpm pipeline fails.
If you haven’t used stable boxes before or are interested in the details of how they are created, please read the documentation here. There are some small differences from our traditional box-spin-up workflow.
Let me know if there are any questions!