Debugging

Use this skill when the job is to turn a concrete failure into a bounded diagnosis loop.

The center of the skill is small and repeatable:

1. define the failing behavior in testable terms,
2. build or confirm the cheapest reliable reproducer,
3. isolate the narrowest failing boundary,
4. run one discriminating check per hypothesis,
5. verify the fix under the same conditions.

Read references/handoff-boundaries.md before taking work that may belong to log-analysis, testing-strategies, code-review, or performance-optimization. Read references/debug-loop.md for the full experiment-loop scaffolding. Read references/mode-selection-and-fast-checks.md when the case is clearly a regression, flake, env/config mismatch, or artifact-led investigation.