implement-patch skill

Implement Patch

When to Use

Use after independent validation confirms one claim. Read the record contract. Before target commands, follow its project guidance.

When NOT to Use

Do not use for speculative bug hunting, proof of a completed patch, or a change that cannot be exercised by the local compiler or runtime.

Procedure

1. Before editing, run uv run --no-project <script> check --before-repair <run-dir> with the record validator. If this check fails, stop and return its errors for an INCONCLUSIVE report. The gate requires finding.repair_scope with a usable case plan and a consistent attempt count. Use the declared scope as the repair brief. Identify the broken invariant and search within its boundary for every instance of the same violation. Read the threat model only to preserve intended behavior; it is not a gate.

2. Run the project's existing suite and record its results. Write a regression test that fails on the baseline for the named bug and any fixed variant. Observe the failure. Fix the invariant within the repair brief with the smallest reviewable change.

3. Run the regression test and full existing suite again. Compare before and after failures. Fix new failures or explain a pre-existing one from receipts.

4. Record every variant as fixed or not_fixed with a reason. Produce exactly one local commit. Never push or open a PR. From the baseline, write fix.patch for production changes and tests.patch for test changes in patch/attempt-N/.

5. Write patch.json with the two commit SHAs, changed-file and line counts, variants, suite results, and your agent identity. If the attempt produced no commit, record patch_commit: null and return it as failed. Manifest the entire attempt directory, including both patch files and the record, using uv run --no-project <script> manifest <patch-attempt-dir>. Check it with the record validator.

   Patch record schema:

{
  "schema_version": 1,
  "attempt": 1,
  "baseline_commit": "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
  "patch_commit": "bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb",
  "files_changed": 2,
  "lines_added": 3,
  "lines_removed": 1,
  "variants": [],
  "suite_before": {"command": "pytest", "passed": 9, "failed": 1, "skipped": 0},
  "suite_after": {"command": "pytest", "passed": 10, "failed": 0, "skipped": 0},
  "agent": "patcher-1"
}

Rationalizations to Reject

Shortcut	Required action
Only the reported line matters.	Search for the same invariant violation.
Minimal means the fewest lines.	Make the smallest reviewable invariant-level fix.
Tests pass after the patch.	Show the regression test failed before it.