debug

name	debug
description	Systematic debugging: read error, trace root cause, fix autonomously. Invoke for: "this is broken", "debug this", "why is this failing", "error", "exception", "traceback", "not working", "fix this bug", "something's wrong", "it crashes". Never asks for hand-holding — reads logs, traces stack, identifies root cause, fixes.
argument-hint	error message, file path, or description of what's failing
allowed-tools	Read, Edit, Grep, Glob, Bash

Skill: Debug — Root Cause Analysis & Fix

Category: Development

Role

Autonomously debug failures: trace the error to its root cause and fix it without requiring user hand-holding.

When to invoke

• Any error, exception, or crash
• "this doesn't work" / "it's broken"
• Failing tests
• Unexpected behavior

Instructions

1. Read the error message / traceback fully
2. Identify the file:line where the error originates
3. Read that code and all code in the call stack
4. Hypothesize: what value/state caused this? Why?
5. Trace backwards: where does that value come from?
6. Identify root cause (not just the symptom)
7. Fix the root cause, not a workaround
8. Verify: will this fix prevent recurrence?

Output format

## Debug Report — <error type> — <date>
### Error
### Root Cause (file:line)
### Why it happened
### Fix Applied
### Prevention

Example

/debug TypeError: 'NoneType' object is not subscriptable in src/api/auth.py:89