Normally bucket definitions also contain builder definitions.
At least a builder belongs to a bucket, so whatever pushes builder definitions will need to know buckets.

What system will push builder definitions?
Will different partner projects (buckets) have different sets of builders?

We'll probably have a Scheduler-scheduled task that pushes the builders and buckets based on information stored in DLM and maybe some supplemental information stored in checked-in config files. We are blocked from doing that until all builder and project relationships have been imported into DLM. As a short-term hack, we might export all currently-known builders in a single bucket and then move them to their project bucket, later.

Each project bucket will have exclusive ownership of builders. Additionally, there will be some "meta" bucket to host parent builders for CQ, Post-submit, and Release, as well as for administrative tasks like the one proposed above.