Use when debugging any bug. Enforces a 5-phase protocol where code edits are blocked until root cause is confirmed. Prevents premature fix attempts.
AI coding agents see an error and immediately edit code. They guess at fixes, get it wrong, and spiral. This skill enforces a strict 5-phase protocol where you CANNOT edit source code until the root cause is identified and confirmed.
Based on claude-debug (full plugin with PreToolUse hook enforcement).
Use this skill when:
Run the failing command/test. Capture the exact error. Run 2-3 times for consistency.
Read code. Add diagnostic logging marked // DEBUG. Re-run with diagnostics. Binary search to narrow down.
// DEBUG marked logging is allowedAnalyze WHY at the isolated location. Use "5 Whys" technique. Remove debug logging.
State: "This is my root cause analysis: [explanation]. Do you agree, or should I investigate further?"
WAIT for user confirmation. Do NOT proceed without it.
Remove all // DEBUG lines. Apply minimal change addressing confirmed root cause.
Run original failing test — must pass. Run related tests. For intermittent bugs, run 5+ times. If verification fails: root cause was wrong, go back to Phase 2.
| Type | Technique |
|---|---|
| Crash/Panic | Stack trace backward — trace the bad value to its source |
| Wrong Output | Binary search — log midpoint, halve search space each iteration |
| Intermittent | Compare passing vs failing run logs — find ordering divergence |
| Regression | git bisect — find the offending commit |
| Performance | Timing at stage boundaries — find the bottleneck |
// DEBUG in phase 2)