Debug Skill

When to use this skill

• runtime errors, flaky tests, wrong outputs
• “it used to work” regressions
• performance or timeout problems (initial triage)

Debug workflow (do not skip steps)

1. Reproduce
   • Capture exact error, inputs, environment, command.
2. Minimize
   • Reduce to smallest repro (one file, one function, smallest dataset).
3. Hypotheses (2–5)
   • Rank by likelihood.
4. Instrument
   • Add temporary logging/assertions or use existing diagnostics.
5. Fix
   • Smallest change that removes root cause.
6. Prevent
   • Add regression test or permanent guard/validation.
7. Verify
   • Run the failing case + relevant suites.

Reporting format

• Symptom
• Repro steps
• Root cause
• Fix
• Regression protection
• Verification