feat: add retry mechanism for UNKNOWN mergeable status PRs

[keithwillcode]

What does this PR do?

Adds a retry mechanism to the Devin PR Conflict Resolver workflow to handle PRs where GitHub hasn't finished computing the mergeable status.

Problem: When a PR merges into main, GitHub needs to recompute the mergeable status for all open PRs. The workflow runs so fast after a merge that many PRs show UNKNOWN status (100+ PRs in recent runs), meaning actual conflicts could be missed.

Solution:

• Collect PRs with UNKNOWN mergeable status during the initial pass
• Wait 20 seconds for GitHub to compute the status
• Re-query those specific PRs via REST API (which can trigger GitHub to compute the status)
• Process any newly discovered conflicts

The code was refactored to extract a processPR helper function to avoid duplicating the conflict detection logic between the initial pass and retry pass.

Updates since last revision

Addressed Cubic AI review feedback by having processPR return isTargetPR consistently for both conflict and unknown cases, removing redundant filtering logic in the main loop that was re-checking draft status and devin label (already checked in processPR).

Mandatory Tasks (DO NOT REMOVE)

• I have self-reviewed the code (A decent size PR without self-review might be rejected).
• I have updated the developer docs in /docs if this PR makes changes that would require a documentation change. N/A - workflow change only.
• I confirm automated tests are in place that prove my fix is effective or that my feature works. N/A - GitHub Actions workflow, can only be tested by running the workflow.

How should this be tested?

1. Trigger the workflow manually via workflow_dispatch or wait for a PR to merge to main
2. Check the workflow logs for:
   • "X PRs have UNKNOWN mergeable status, waiting 20 seconds before retrying..."
   • "Retrying X PRs via REST API..."
   • "PR #X retry result: mergeable=MERGEABLE/CONFLICTING/UNKNOWN"
3. Verify that PRs with conflicts are correctly identified after the retry

Human Review Checklist

• Verify processPR returns consistent data structure (isTargetPR included in both conflict and unknown cases)
• Verify the retry loop correctly handles the returned values

Checklist

• My code follows the style guidelines of this project
• I have checked if my changes generate no new warnings

---

Requested by: @keithwillcode
Link to Devin run

[devin-ai-integration]

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[cubic-dev-ai]

1 issue found across 1 file

Prompt for AI agents (all issues)

Check if these issues are valid — if so, understand the root cause of each and fix them.


<file name=".github/workflows/devin-conflict-resolver.yml">

<violation number="1" location=".github/workflows/devin-conflict-resolver.yml:151">
P2: Redundant filtering logic - `processPR` already checks for drafts and the devin-conflict-resolution label before returning `{ unknown: true }`. Re-checking these conditions here defeats the purpose of extracting `processPR` to centralize the logic. Consider having `processPR` return `{ unknown: true, isTargetPR }` (like the conflict case) and simplifying this to just push the PR to `unknownPRs`.</violation>
</file>

_{Reply with feedback, questions, or to request a fix. Tag @cubic-dev-ai to re-run a review.}

[github-actions]

Devin AI is addressing Cubic AI's review feedback

A Devin session has been created to address the issues identified by Cubic AI.

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4 Skipped Deployments

Project	Deployment	Review	Updated (UTC)
api-v2	Ignored	Preview	Jan 13, 2026 1:56am
cal	Ignored		Jan 13, 2026 1:56am
cal-companion	Ignored	Preview	Jan 13, 2026 1:56am
cal-eu	Ignored		Jan 13, 2026 1:56am

[volnei]

Solid