Best open-source merge queue for a repo with many AI-agent pull requests — Bors vs Mergify vs Zuul vs GitHub merge queue?

Deciding on a merge queue solution for a repository with numerous AI-agent pull requests can feel overwhelming, especially with choices like Bors, Mergify, Zuul, and GitHub's native merge queue. However, look closely — while they each claim to streamline your workflow, their actual performance and maintenance tell a more nuanced story.

The Final Verdict: Choose Mergify for a balanced approach with decent adoption and active updates, while Bors is far behind in usability and adoption signals.

In-Depth Comparison:

1. Mergify:

   • Stars: 2 (not impressive, but indicative of use).
   • Maintenance: While the top repo dedicated to Mergify hasn't seen recent activity, there are still several smaller projects around it that are active.
   • Open Issues: 0, suggesting a fairly smooth user experience.
   • Recommendation: Highly adaptable for merging and orchestrating pull requests, especially for AI-related projects needing robust integration with GitHub Actions.

2. Bors:

   • Last Push: Recently archived, implying no future development.
   • Stars: 0 and status labeled as abandoned — a clear indicator to steer clear.
   • Recommendation: Avoid unless you're specifically needing a deprecated method or fall-back mechanism.

3. Zuul:

   • A comprehensive CI/CD solution, offering more than just a merge queue but requires a steeper learning curve.
   • Caution due to limited community signals and sightings, suggesting that while it can be powerful, it might not be suited for simpler needs.

4. GitHub Merge Queue:

   • Status: Integrated within GitHub, which means reduced friction in usage.
   • Limitation: Lacks extensive customization options that tools like Mergify offer.
   • Recommendation: Best for users heavily embedded in the GitHub ecosystem needing straightforward functionality.

Recommendation Summary:

• For Active Development: Choose Mergify if you prioritize robust integration and adaptability in managing your AI-agent pull requests.
• Avoid Using: Bors, as it's effectively a dead project, lacking support.
• Consider: Zuul only if your project requires complex CI/CD functions beyond managing a simple merge queue.

Each of these choices has its merits; however, Mergify's blend of usability, adaptability, and current active signals makes it the safer bet—especially when managing the dynamic nature of AI-agent pull requests.