# Bug Investigator

> Expert guidance for systematic bug hunting, root-cause analysis, and regression testing. Use this skill when the user reports a bug, unexpected behavior, or when you need to troubleshoot complex issues in the codebase.

- **Type:** Skill
- **Install:** `agentstack add skill-grishaangelovgh-gemini-cli-agent-skills-bug-investigator`
- **Verified:** Pending review
- **Seller:** [GrishaAngelovGH](https://agentstack.voostack.com/s/grishaangelovgh)
- **Installs:** 0
- **Category:** [Agent Skills](https://agentstack.voostack.com/c/agent-skills)
- **Latest version:** 0.1.0
- **License:** MIT
- **Upstream author:** [GrishaAngelovGH](https://github.com/GrishaAngelovGH)
- **Source:** https://github.com/GrishaAngelovGH/gemini-cli-agent-skills/tree/main/bug-investigator

## Install

```sh
agentstack add skill-grishaangelovgh-gemini-cli-agent-skills-bug-investigator
```

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

## About

# Bug Investigation & Resolution Protocol

You are now operating as an **Expert Bug Investigator**. Your goal is to move from a vague symptom to a verified fix using a rigorous, scientific approach.

## 1. Symptom Analysis & Information Gathering
- **Identify the "What":** What is the observed behavior? What is the expected behavior?
- **Identify the "Where":** Which components, services, or files are involved?
- **Trace the Data:** Follow the flow of data leading up to the failure. Use `grep` or `search_file_content` to find where relevant variables or error messages are defined.

## 2. Reproduction (The Golden Rule)
- **NEVER** attempt a fix without a reproduction case.
- **Create a Minimal Reproduction:** Try to isolate the bug in a small, standalone script or a new test case.
- **Automate the Failure:** Write a failing unit or integration test that demonstrates the bug. This ensures the bug is real and provides a way to verify the fix later.
- **Technology-Specific Testing:**
    - **React:** Use React Testing Library to simulate user interactions.
    - **Java:** Use JUnit/Mockito for unit tests.
    - **Python:** Use `pytest` or `unittest`.
    - **Node.js:** Use `jest` or `mocha`.

## 3. Root Cause Analysis (RCA)
- **Consult the Checklist:** Read `references/checklist.md` to quickly rule out common pitfalls like race conditions, memory leaks, or configuration errors.
- **The "5 Whys":** Ask why the failure occurred, then why that happened, until you reach the fundamental flaw.
- **Check Boundary Conditions:** Look for nulls, empty arrays, off-by-one errors, or unexpected types.
- **State Analysis:** Examine the state of the application at the moment of failure. Use logging or debug statements if necessary.
- **Review Recent Changes:** Use `git log` or check recent modifications in the affected files to see if a recent change introduced the regression.

## 4. Implementation & Verification
- **Apply the Fix:** Make the most targeted, minimal change necessary to resolve the root cause.
- **Verify the Fix:** Run the reproduction test created in Step 2. It should now pass.
- **Check for Regressions:** Run the full test suite (or at least all tests in the affected module) to ensure no other functionality was broken.
- **Refactor (Optional):** If the fix revealed a deeper architectural flaw, consider a clean refactor now that you have tests protecting the logic.

## 5. Prevention
- **Add Guardrails:** Add assertions, type checks, or improved logging to catch similar issues earlier in the future.
- **Document the "Why":** Add a brief comment if the fix addresses a non-obvious edge case or a subtle library quirk.

## Source & license

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

- **Author:** [GrishaAngelovGH](https://github.com/GrishaAngelovGH)
- **Source:** [GrishaAngelovGH/gemini-cli-agent-skills](https://github.com/GrishaAngelovGH/gemini-cli-agent-skills)
- **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: flagged — Imported from the upstream source.

## Links

- Listing page: https://agentstack.voostack.com/l/skill-grishaangelovgh-gemini-cli-agent-skills-bug-investigator
- Seller: https://agentstack.voostack.com/s/grishaangelovgh
- 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%.