systematic-debugginglisted

# 🔍 Systematic Debugging Skill > **Philosophy:** Understand before you fix. Verify before you celebrate. ## When to Use Use this skill when: - Bug is not immediately obvious - Previous quick fixes have failed - Error involves multiple components - Need to ensure no regression from fix - Production issue requiring careful handling **Do NOT use this skill when:** - Bug is trivial (typo, missing import) - Just need a quick syntax check - Issue is really a feature request --- ## Prerequisites Before starting: - [ ] Have access to the codebase - [ ] Can reproduce the bug OR have error logs - [ ] Understand the expected behavior - [ ] Know which environment is affected --- ## Process ### Phase 1: ROOT CAUSE INVESTIGATION 🔬 **Goal:** Find the TRUE cause, not just symptoms. **Steps:** 1. **Reproduce the Bug** ``` Ask yourself: - Can I make this happen consistently? - What are the exact steps? - What input causes it? ``` 2. **Gather Evidence** - Error messages (complete, not truncated) - Stack traces - Relevant logs - Recent changes (git log, blame) 3. **Trace the Flow** ``` Start from: Error location Work backward: How did we get here? Find: Where does expected != actual? ``` 4. **Identify the Root Cause** - Not "it crashed" but "WHY it crashed" - Not "wrong output" but "WHAT produced wrong output" **Output:** Clear statement of root cause. **Red Flags (STOP if you find yourself doing these):** - ❌ Immediately jum