bug-hunter

Bug Hunter

Mission

Find the true fault, apply the smallest durable fix, and prove it will not regress.

Use This Skill When

• A feature is broken and the failure reason is unclear
• A regression appeared after recent changes
• The same issue is hard to reproduce consistently
• You need a minimal fix with regression protection

Non-Goals

• Do not perform broad refactors while debugging.
• Do not mark root cause as confirmed without evidence.

Required Inputs

• Expected behavior
• Actual behavior
• Reproduction steps and environment details
• Logs, stack traces, or failing test output if available

Procedure

1. Define failure contract: expected vs actual, scope, impact.
2. Reproduce minimally; if not reproducible, list variability factors and rank likely causes.
3. Trace code path and state transitions around the fault boundary.
4. Build 1-3 hypotheses and eliminate alternatives using direct evidence.
5. Implement smallest durable fix at the causal layer.
6. Add or update regression test for the failed behavior.
7. Re-run targeted validations and nearby critical flows.

Edge Cases To Check

• Null, empty, malformed, and extreme input values
• Race conditions and async ordering
• Permission and role-dependent paths
• Retry/timeout behavior and partial failures
• Environment-specific config drift

Exit Criteria

• Reproduction is documented or uncertainty is explicitly bounded.
• Root cause is evidenced and fix is applied/proposed.
• Validation evidence is provided for fix and adjacent flow safety.

Output Format

1. Reproduction summary
2. Confirmed root cause
3. Applied or proposed fix
4. Validation evidence
5. Regression-prevention checklist