# Systematic Debugging

> Use for ANY bug, test failure, crash, or unexpected behavior. Forces

- **Type:** Skill
- **Install:** `agentstack add skill-archive228-loopkit-systematic-debugging`
- **Verified:** Yes — security-reviewed for prompt injection and unsafe behavior
- **Seller:** [Archive228](https://agentstack.voostack.com/s/archive228)
- **Installs:** 0
- **Category:** [Agent Skills](https://agentstack.voostack.com/c/agent-skills)
- **Latest version:** 0.1.0
- **License:** MIT
- **Upstream author:** [Archive228](https://github.com/Archive228)
- **Source:** https://github.com/Archive228/loopkit/tree/main/skills/systematic-debugging

## Install

```sh
agentstack add skill-archive228-loopkit-systematic-debugging
```

Requires the [AgentStack CLI](https://agentstack.voostack.com/docs/cli). Works with Claude Code, Cursor, and any MCP-compatible agent.

## About

# Systematic Debugging

The single most expensive agent failure: seeing an error and immediately generating a
"fix" based on the error type, without reading what actually happened. Don't.

## The loop

1. **Read the whole error.** The entire message and stack trace. A TypeError can mean a
   hundred different things — the trace tells you which one. Quote the exact line that throws.

2. **Reproduce it first.** If you can't reproduce it, you can't verify a fix. Write the
   smallest input that triggers it. "I think this fixes it" is gambling, not debugging.

3. **Form one hypothesis, name it.** "I think the value is null because the upstream call
   returns 204 with no body." State it before you touch anything.

4. **Change one thing. Test. Repeat.** If you change three things and it works, you don't
   know which one fixed it — and the other two may have added new bugs.

5. **Fix the root cause, not the symptom.** A null check that hides a null is not a fix.
   Find why it's null. The underlying bug will resurface differently if you only patch the crash.

## Stop conditions

- If 3 hypotheses fail, STOP and report: what you tried, what you saw, what you suspect.
  "I've tried X and Y, here's the output, I think it's Z but I'm not sure" beats 20 silent
  random attempts.
- Never add a workaround you don't understand.

## Output

End with: the root cause (one sentence), the minimal fix, and the test that now proves it.

## Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

- **Author:** [Archive228](https://github.com/Archive228)
- **Source:** [Archive228/loopkit](https://github.com/Archive228/loopkit)
- **License:** MIT

Install and usage instructions live in the source repository linked above.

## Pricing

- **Free** — Free

## Security capabilities

Automated source analysis of v0.1.0 — what this tool can access:

- **Network access:** no
- **Filesystem access:** no
- **Shell / process execution:** no
- **Environment & secrets:** no
- **Dynamic code execution:** no

*"Yes" means the capability is present in the source — more access means more to trust, not that it is unsafe.*


## Versions

- **0.1.0** — security scan: passed — Imported from the upstream source.

## Links

- Listing page: https://agentstack.voostack.com/l/skill-archive228-loopkit-systematic-debugging
- Seller: https://agentstack.voostack.com/s/archive228
- Browse the marketplace: https://agentstack.voostack.com/browse

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Listed on AgentStack — the marketplace for AI agent skills and MCP servers. Every listing is security-reviewed. Creators keep 70%.