diagnosing-bugs
Diagnosis loop for hard bugs and performance regressions. Use when the user says "diagnose"/"debug this", or reports something broken/throwing/failing/slow.
Profile →npx skills add sickn33/agentic-awesome-skills --skill diagnosing-bugs --agent claude-code
Same command for any agent — swap --agent for codex, cursor, copilot.
Weekly change comes from our own snapshots, not the repository page — it measures attention, not adoption.
# Diagnosing Bugs ## When to Use Use when this workflow matches the user request: Use this skill for its documented workflow. _Source: [mattpocock/skills](https://github.com/mattpocock/skills) (MIT)._ A discipline for hard bugs. Skip phases only when explicitly justified. When exploring the codebase, read `CONTEXT.md` (if it exists) to get a clear mental model of the relevant modules, and check ADRs in the area you're touching. ## Phase 1 — Build a feedback loop **This is the skill.** Everything else is mechanical. If you have a **tight** pass/fail signal for the bug — one that goes red on _this_ bug — you will find the cause; bisection, hypothesis-testing, and instrumentation all just consume it. If you don't have one, no amount of staring at code will save you. Spend disproportionate effort here. **Be aggressive. Be creative. Refuse to give up.** ### Ways to construct one — try them in roughly this order 1. **Failing test** at whatever seam reaches the bug — unit, integration, e2e. 2. **Curl / HTTP script** against a running dev server. 3. **CLI invocation** with a fixture input, diffing stdout against a known-good snapshot. 4. **Headless browser script** (Playwright / Puppeteer)
- When to Use
- Phase 1 — Build a feedback loop
- Ways to construct one — try them in roughly this order
- Tighten the loop
- Non-deterministic bugs
- When you genuinely cannot build a loop
- Completion criterion — a tight loop that goes red
- Phase 2 — Reproduce + minimise
- Minimise
- Phase 3 — Hypothesise
- Phase 4 — Instrument
- Phase 5 — Fix + regression test
- Phase 6 — Cleanup + post-mortem
- Limitations
What does the diagnosing-bugs skill do?
Diagnosis loop for hard bugs and performance regressions. Use when the user says "diagnose"/"debug this", or reports something broken/throwing/failing/slow.
How do I install it?
Run `npx skills add sickn33/agentic-awesome-skills --skill diagnosing-bugs --agent claude-code` — it drops the skill into your project so the agent can pick it up. Swap the --agent value for codex, cursor or copilot if you use one of those.
Where does this skill come from?
From sickn33/agentic-awesome-skills, a repository with 44,414 stars. We read it straight from the repository tree rather than a submitted listing, so what you see here is what is actually published.
Is a popular skill a good skill?
Not necessarily. Stars measure attention, not adoption — a repository can trend for a week and be abandoned. That is why we show the weekly change from our own snapshots next to the total, instead of a single flattering number.