Debugging Skills

A collection of systematic debugging methodologies that ensure thorough investigation before attempting fixes.

Available Sub-Skills

Systematic Debugging

Location: systematic-debugging/SKILL.md

Four-phase debugging framework: Root Cause Investigation → Pattern Analysis → Hypothesis Testing → Implementation. The iron law: NO FIXES WITHOUT ROOT CAUSE INVESTIGATION FIRST.

Root Cause Tracing

Location: root-cause-tracing/SKILL.md

Trace bugs backward through the call stack to find the original trigger. Don't fix symptoms - find where invalid data originated and fix at the source.

Defense-in-Depth Validation

Location: defense-in-depth/SKILL.md

Validate at every layer data passes through to make bugs structurally impossible. Four layers: Entry Point → Business Logic → Environment Guards → Debug Instrumentation.

Verification Before Completion

Location: verification-before-completion/SKILL.md

Run verification commands and confirm output before claiming success. The iron law: NO COMPLETION CLAIMS WITHOUT FRESH VERIFICATION EVIDENCE.

When to Use

• Bug in production → Start with systematic-debugging
• Error deep in stack trace → Use root-cause-tracing
• Fixing a bug → Apply defense-in-depth after finding root cause
• About to claim "done" → Use verification-before-completion

Quick Dispatch

Symptom	Sub-Skill
Test failure, unexpected behavior	systematic-debugging
Error appears in wrong location	root-cause-tracing
Same bug keeps recurring	defense-in-depth
Need to confirm fix works	verification-before-completion

Core Philosophy

"Systematic debugging is FASTER than guess-and-check thrashing."

From real debugging sessions:

• Systematic approach: 15-30 minutes to fix
• Random fixes approach: 2-3 hours of thrashing
• First-time fix rate: 95% vs 40%