Debug

Systematic debugging using the persona-debugger agent methodology. Apply six steps to find and fix the root cause.

6-Step Methodology

Step 1: Reproduce

Understand and reproduce the issue from the given input:

• Parse error messages, stack traces, or symptom descriptions
• Identify reproduction steps
• Confirm the failure is consistent or intermittent

Step 2: Isolate

Narrow down the root cause:

• Identify the failing code path
• Use bisection or elimination to isolate the component
• Check recent changes with git log --oneline -20

Step 3: Analyze

Examine code, logs, and state:

• Read the relevant source files
• Check error handling and edge cases
• Trace data flow through the failure path

Step 4: Hypothesize

Form theories about the bug:

• List 2-3 candidate root causes
• Rank by likelihood based on evidence
• Identify what evidence would confirm/reject each

Step 5: Test

Validate hypotheses:

• Add strategic debug output or assertions
• Test each hypothesis against the evidence
• Confirm root cause with high confidence

Step 6: Fix

Implement and verify the solution:

• Apply the minimal fix that addresses the root cause
• Add a regression test to prevent recurrence
• Run existing tests to verify no regressions

Report

## Debug Complete

**Issue**: <brief description>
**Root Cause**: [file:line] - <explanation>
**Confidence**: [High/Medium/Low]
**Fix Applied**: Yes/No

### Evidence
- <key evidence supporting diagnosis>

### Prevention
- <regression test added>
- <recommendations to prevent similar issues>

Next Steps:
- `/arc:core:verify --post` to run full verification
- `/arc:specialized:bug` for deeper investigation if fix didn't resolve