Reproduce Bug

Reproduce Bug Command

Look at github issue #$ARGUMENTS and read the issue description and comments.

When I report a bug, don't start by trying to fix it. Instead, start by writing a test that reproduces the bug. Then, have subagents try to fix the bug and prove it with a passing test.

Phase 1: Log Investigation

Run the following agents in parallel to investigate the bug:

1. Task rails-console-explorer(issue_description)
2. Task appsignal-log-investigator(issue_description)

Think about the places it could go wrong looking at the codebase. Look for logging output we can look for.

Run the agents again to find any logs that could help us reproduce the bug.

Keep running these agents until you have a good idea of what is going on.

Phase 2: Visual Reproduction with Playwright

If the bug is UI-related or involves user flows, use Playwright to visually reproduce it:

Step 1: Verify Server is Running

mcp__plugin_compound-engineering_pw__browser_navigate({ url: "http://localhost:3000" })
mcp__plugin_compound-engineering_pw__browser_snapshot({})

If server not running, inform user to start bin/dev.

Step 2: Navigate to Affected Area

Based on the issue description, navigate to the relevant page:

mcp__plugin_compound-engineering_pw__browser_navigate({ url: "http://localhost:3000/[affected_route]" })
mcp__plugin_compound-engineering_pw__browser_snapshot({})

Step 3: Capture Screenshots

Take screenshots at each step of reproducing the bug:

mcp__plugin_compound-engineering_pw__browser_take_screenshot({ filename: "bug-[issue]-step-1.png" })

Step 4: Follow User Flow

Reproduce the exact steps from the issue:

1. Read the issue's reproduction steps
2. Execute each step using Playwright:

• browser_click for clicking elements
• browser_type for filling forms
• browser_snapshot to see the current state
• browser_take_screenshot to capture evidence

1. Check for console errors:

`` mcp__plugin_compound-engineering_pw__browser_console_messages({ level: "error" }) ``

Step 5: Capture Bug State

When you reproduce the bug:

1. Take a screenshot of the bug state
2. Capture console errors
3. Document the exact steps that triggered it

mcp__plugin_compound-engineering_pw__browser_take_screenshot({ filename: "bug-[issue]-reproduced.png" })

Phase 3: Document Findings

Reference Collection:

• [ ] Document all research findings with specific file paths (e.g., app/services/example_service.rb:42)
• [ ] Include screenshots showing the bug reproduction
• [ ] List console errors if any
• [ ] Document the exact reproduction steps

Phase 4: Report Back

Add a comment to the issue with:

1. Findings - What you discovered about the cause
2. Reproduction Steps - Exact steps to reproduce (verified)
3. Screenshots - Visual evidence of the bug (upload captured screenshots)
4. Relevant Code - File paths and line numbers
5. Suggested Fix - If you have one

Source & license

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

• Author: marchatton
• Source: marchatton/agent-skills
• License: MIT
• Homepage: https://www.marchatton.com

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