Migrate from Bors‑NG to Mergify

Bors‑NG orchestrates a “try → staging → master” flow with batch testing and ordered merges. Mergify offers a Merge Queue with similar guarantees plus flexible rules.

• Keep your branch protection and checks
• Define one queue rule in .mergify.yml
• Replace bors r+ approvals with the @mergifyio queue command

• bors r+ approval → @mergifyio queue command
• batch size → Mergify batches with configurable size
• priority → Mergify queue priorities

A queue that only accepts approved pull requests whose checks pass:

queue_rules:
  - name: default
    batch_size: 1
    queue_conditions:
      - base = main
      - check-success = ci
      - "#approved-reviews-by>=1"

queue_conditions gates entry to the queue rather than triggering it: a pull request that matches them is queued once somebody runs @mergifyio queue, which is what bors r+ maps to. To have Mergify queue pull requests on its own rather than on that command, set up Auto-Merge.

If you relied on bors try to validate speculative changes, you can keep a lightweight CI workflow triggered by a label or comment.

Increase throughput with batches and prioritize urgent PRs:

queue_rules:
  - name: default
    batch_size: 3
    queue_conditions:
      - base = main
      - check-success = ci
      - "#approved-reviews-by>=1"

priority_rules:
  - name: urgent
    conditions:
      - label = urgent
    priority: high