Diagnosing Bugs
Diagnosing Bugs is an agent skill (a SKILL.md file) from mattpocock/skills. Diagnosis loop for hard bugs and performance regressions. It works with Claude Code, Codex, Cursor, Gemini CLI, GitHub Copilot and OpenCode and has 303,491 GitHub stars across a repository of 15 listed skills.
github.com/mattpocock/skills/skills/engineering/diagnosing-bugs (opens in a new tab)
Data as of from the GitHub API and skills.sh; description from the skill's SKILL.md. Report an error
- Multi-skill repo
- Plugin marketplace
- Testing & QA
- Active
Add this skill
Claude
This repository is a Claude Code plugin marketplace. In Claude Code:
/plugin marketplace add mattpocock/skills
/plugin install mattpocock-skills@mattpocockIn the Claude apps, zip the diagnosing-bugs folder and upload it under Customize > Skills > + > Upload a skill (code execution must be on).
ChatGPT / Codex
Codex reads skills from .agents/skills/ in a repo or ~/.agents/skills/ for every project:
git clone --depth 1 https://github.com/mattpocock/skills.git
cp -r skills/skills/engineering/diagnosing-bugs .agents/skills/diagnosing-bugs # repo; ~/.agents/skills for all projectsStandalone skills also load in the ChatGPT desktop app.
Cursor
Cursor loads skills from .cursor/skills/ (or ~/.cursor/skills/) and also reads .claude/skills/:
git clone --depth 1 https://github.com/mattpocock/skills.git
cp -r skills/skills/engineering/diagnosing-bugs .cursor/skills/diagnosing-bugs # project; ~/.cursor/skills for all projectsSource (checked Oct 7, 2026): code.claude.com/docs/en/skills (opens in a new tab), code.claude.com/docs/en/plugin-marketplaces (opens in a new tab), support.claude.com/en/articles/12512180-using-skills-in-claude (opens in a new tab), learn.chatgpt.com/docs/build-skills (opens in a new tab), cursor.com/docs/context/skills (opens in a new tab)
What this skill does
Diagnosis loop for hard bugs and performance regressions. Use when the user says "diagnose"/"debug this", or reports something broken/throwing/failing/slow. A discipline for hard bugs. Skip phases only when explicitly justified.
When it triggers
- Use when the user says "diagnose"/"debug this", or reports something broken/throwing/failing/slow.
- "diagnose"
- "debug this"
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How do I install the Diagnosing Bugs skill?
In Claude Code, run /plugin marketplace add mattpocock/skills and then /plugin install mattpocock-skills@mattpocock. For Codex or Cursor, copy the diagnosing-bugs folder into .agents/skills/ or .cursor/skills/.
Is the Diagnosing Bugs skill free?
Yes. The repository is open source under the MIT license.
Is Diagnosing Bugs maintained?
The repository's most recent commit was on Oct 19, 2026. Its latest release is v1.3.1. appsgit only lists skills from repositories with a commit in the last six months.