Debug Mode Skill — Development skill for Claude Code

Debug Mode for Claude Code

**Stop guessing. Start debugging.**

A [Claude Code skill](https://docs.anthropic.com/en/docs/claude-code/skills) that brings hypothesis-driven, instrumented debugging to the terminal. Instead of guessing and patching, Claude Code will systematically reproduce your bug, add tagged logs, analyze runtime behavior, fix the root cause, and write a regression test.

The Problem

AI coding assistants guess at fixes. They see an error, pattern-match to a solution, and hope it works. When it doesn't, they guess again. This is expensive, slow, and produces fragile code.

The Solution

Debug Mode forces a disciplined loop:

Hypothesize → Reproduce → Instrument → Analyze → Reset → Fix → Verify

Every fix is backed by evidence. Every bug gets a regression test. No guessing.

How It Works

The 9-Phase Loop

Phase	What Happens
0. Safety	Create git branch + stash uncommitted work
1. Discover	Scan project for test infra, scripts, recent changes
2. Hypothesize	Generate 3-5 ranked theories with evidence criteria
3. Reproduce	Write repro script/test and commit it
4. Instrument	Add [DEBUG-MODE] tagged logs (dirtying the working tree)
5. Analyze	Run reproduction, capture logs to file, grep intelligently
6. Reset	git restore . — perfectly removes all debug logs
7. Fix	Implement fix at root cause (not symptom)
8. Verify	Red-to-green check using the committed repro

The Commit-Then-Instrument Pattern

This is the key insight. LLMs are bad at surgically removing debug logs — they leave hanging brackets, break indentation, and corrupt syntax. Debug Mode solves this:

1. Write reproduction test/script
2. Commit it (git commit -m "chore: add failing reproduction")
3. Add [DEBUG-MODE] logs everywhere (dirty the working tree)
4. Analyze the logs
5. git restore . — instantly removes ALL instrumentat