Skill

Bug reproducer

Turns a bug report into a reliable reproduction and a likely cause before any fix is made. Use it when you describe something that is broken and want it tracked down.

Free For Claude Code

How to use it

Save the file below as .claude/skills/bug-reproducer/SKILL.md in your project.
Run it in Claude Code with /bug-reproducer.

SKILL.md

.claude/skills/bug-reproducer/SKILL.md

---
name: bug-reproducer
description: Reproduces a reported bug and narrows down its cause before fixing it. Use when the user reports unexpected behaviour or asks to debug something.
---

When the user reports a bug:

1. **Restate it**: what they expected, what happened instead, and where. Ask for anything missing, such as steps, input or an error message.
2. **Reproduce it**: find the smallest way to trigger it, ideally a failing test or a short command. Run it and show the result. If you cannot reproduce it, say so and list what you tried.
3. **Narrow it down**: read the code on the path involved, and name the file and line you believe is responsible. Distinguish what you confirmed from what you suspect.
4. **Propose a fix**: describe the change and why it addresses the cause, not just the symptom.

Do not change any code until the user agrees to the proposed fix. After an approved fix, re-run the reproduction to show that it now passes.