# Debug Error

> Use when the user has an error, bug, stack trace, failing test, or unexpected behavior to diagnose.

- Skill: `majiayu000/debug-error` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds add majiayu000/debug-error`
- Raw SKILL.md: https://api.skillmd.com/api/skills/majiayu000/debug-error/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: majiayu000 (https://skillmd.com/u/majiayu000)
- Updated: 2026-09-09
- Page: https://skillmd.com/skills/majiayu000/debug-error

---


Debug and fix: **$ARGUMENTS**

## Steps

1. **Parse the error**
   - Identify error type (runtime, compile, type, network, etc.)
   - Extract file paths and line numbers from stack trace
   - Identify the error message

2. **Find the source**
   - Read the file(s) mentioned in the stack trace
   - If no stack trace, Grep for the error message in codebase
   - Read surrounding code to understand context

3. **Trace the root cause**
   - Follow the call chain backwards
   - Check recent git changes that might have caused it:
     ```
     git log --oneline -10
     git diff HEAD~3
     ```
   - Look for common causes: null/undefined, wrong types, missing imports, race conditions

4. **Implement the fix**
   - Fix the root cause, not just the symptom
   - Handle edge cases that led to the error

5. **Verify**
   - Run the failing scenario
   - Run related tests
   - Check for similar patterns elsewhere:
     ```
     grep -r "similar_pattern" src/
     ```

6. **Report**
   ```
   ## Bug Fix Report

   ### Error
   [original error]

   ### Root Cause
   [why it happened]

   ### Fix
   [what was changed and why]

   ### Files Modified
   - [file] — [change]

   ### Verified
   - [how it was tested]
   ```

<!-- Skill by Huzefa Nalkheda Wala | github.com/huzaifa525 | claude-code-optimizer -->