Bug Investigation & Fix Planning

Investigate bugs from any input — error logs, stack traces, user reports. Creates an architectural fix plan with exact code specifications.

Use the right skill:

• Bug fixes → bug (this skill)
• Quick debugging → debug
• New features → plan via /arc:core:plan
• Code quality → quality

Note: Only view-only git commands allowed (no state modifications).

Arguments

Takes any input:

• Error logs: "TypeError: 'NoneType' at auth.py:45"
• Stack traces: "$(cat stacktrace.txt)"
• Log files: ./logs/error.log
• User reports: "Login fails when user has no profile"
• Diagnostic instructions: "Check docker logs for api-service"

Instructions

Step 1: Process Input

Parse input:

• If file path → use Read tool to load contents
• If inline text → extract error signals
• If diagnostic instructions → execute via Bash:
  • Docker logs: docker logs <container> --tail 500
  • Process logs: journalctl -u <service>

Step 2: Launch Agent

Launch background agent with gathered context:

REQUIRED Task tool parameters:

subagent_type: "arc:bug-plan-creator"
run_in_background: true
prompt: "Investigate bug and create fix plan:\n\n<gathered context>"

Output a status message like "Investigating bug..." and end your turn. The system wakes you when the agent finishes.

Step 3: Report Result

## Bug Investigation Complete

**Plan**: openspec/plans/YY-MM-DD-bug-<name>-<hash5>.md
**Severity**: [Critical/High/Medium/Low]
**Root Cause Confidence**: [High/Medium/Low]

Root Cause: [file:line] - [brief description]

Next Steps:
1. Review the fix plan
2. Execute: `/arc:core:execute --source plan --plan-path <plan-path>`

Error Handling