Bug diagnoser
Describe what is broken or slow. Get the cause found step by step and the fix checked.
Bug diagnoser is a free AI skill for the job "Test and fix code". Give the instructions to an AI assistant that supports the required files and tools, then review its output.
Free · No account · MIT licence · Made by Matt Pocock · Thinking: high
Made by Matt Pocock. See the original on GitHub; we copied it as it is, with its licence.
What it does
A step-by-step method for the bugs that resist quick fixes, whether something is broken or just slow. It ends with a cause found and a fix that was checked. The key idea is to build a tight pass or fail signal first. That might be a failing test, a request script, a command with sample input, a browser script or a replay of saved data. Once you can reproduce the bug on demand, the skill narrows it down with bisecting, guessing causes and adding logs. Secrets are replaced with a redaction marker before anything is shown. If the bug cannot be reproduced, it says so and asks you for more.
You give it
- A description of what is broken or slow
- Any error output or logs
- Steps or data that trigger it (optional)
- Access to the code
You get
- A repeatable way to trigger the bug
- A narrowed-down cause
- A tested fix
- Notes with secrets removed
Use it when
- A bug shows up only sometimes and you cannot trigger it.
- Something got slower and you do not know what changed.
- You tried several fixes and none worked.
- You need a repeatable test that proves a bug is fixed.
How to use it
- Add it to your AI once: download it and add the folder to Claude, ChatGPT or Codex as a skill.
- Ask for the job in your own words. Your AI opens the skill when it fits.
- It works best when your AI can run code and read your project files.