Safety at Scale: Introducing check and Per-Commit Validation in pickman

Automating cherry-picks with AI (as seen in our introduction to pickman) was a huge step forward for U-Boot Concept maintenance. However, as any maintainer knows, theory and practice often collide when you try to apply 260+ commits in a single session.

After several weeks of real-world use, we’ve identified three “stress points” in large-scale cherry-picking:

1. The Detail Gap: It’s hard to see if a cherry-pick subtly mangled the code just by looking at a GitLab GUI.
2. Ghost Commits: Effort is often wasted cherry-picking commits that were already merged via a different path.
3. Delayed Failure: Building only at the end of a 200-commit series means catching a mistake at commit #5 requires a massive amount of backtracking.

A recent series introduces a suite of safety features to address these challenges.

1. The check Command: Catching “Mangled” Commits

The star of this update is the new check command. It provides a simple, high-level audit of the “delta” between an original commit and its cherry-picked version.

If a cherry-pick results in a significantly different file structure or line count compared to the original, pickman flags it for review:

 Cherry-pick Delta% Original   Subject
 ----------- ------ ---------- -------
 aaea489b2a     100 9bab7d2a7c net: wget: let wget_with_dns work with...
 e005799d8f      33 15e0c5e390 lmb: Remove lmb_alloc_addr_flags()
 c347fb4b1a      41 99145eec2d x86: select CONFIG_64BIT for X86_64
 12 problem commit(s) found

By adding the -d (diff) option, you can see a direct patch-to-patch comparison, making it easy to spot exactly where a conflict resolution went off the rails.

2. Move Fast, Check Often: Per-Commit Validation

We have updated the AI agent prompt to be much more proactive. Instead of blindly applying a series and hoping for the best, the agent now:

• Checks Deltas Immediately: After every successful cherry-pick, it compares the new commit stat against the original.
• Builds Every Commit: It runs buildman after every single commit. This ensures the tree remains in a “good” state throughout the entire process.
• Self-Correction: If a delta is too large (>20%), the agent will now attempt to reset and manually apply the changes using git apply --3way before moving forward.

3. Smarter “Already-Applied” Detection

Duplicate commits are a constant headache. pickman now includes a robust detection system that looks for matching subjects in the target branch (ci/master) before it starts work.

It doesn’t just match text; the agent now compares actual patch content. It will only skip a commit if it can be verified as the same with good confidence, drastically reducing false positives.

Key Commands in this Series

Quality and Compliance

Beyond features, this series brings the pickman codebase up to production standards. We’ve enforced 80-column compliance, cleared numerous pylint warnings, and transitioned to using Named Tuples (like AgentCommit) to ensure the code is as readable as the commits it manages.

These refinements mark a step along the path to turn pickman from an experimental AI helper into a robust repository maintenance tool.