⌘ /fix

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description: Debug and fix bugs, errors, or unexpected behavior disable-model-invocation: false

Investigate, diagnose, and fix bugs or unexpected behavior in the codebase.

Process

Use the debugging skill from bushido to:

1. Reproduce the issue: Confirm the bug exists and understand when it happens
2. Gather information: Error messages, logs, stack traces, user reports
3. Form hypothesis: What might be causing the issue?
4. Investigate: Use debugging tools, add logging, trace execution
5. Identify root cause: Find the actual source of the problem
6. Implement fix: Change code to resolve the issue
7. Verify fix: Confirm the bug is resolved and no new issues introduced
8. Add regression test: Prevent the bug from returning

Bug Fixing Principles

Understand before fixing:

• Don't guess and patch - find the root cause
• Reproduce reliably before attempting fix
• Understand why the bug exists, not just symptoms

Fix properly:

• Fix the cause, not symptoms
• Consider edge cases and similar issues
• Add tests to prevent regression
• Document why the fix works

Verify thoroughly:

• Original issue resolved
• No new bugs introduced
• Related scenarios still work
• Tests pass (existing + new)

Examples

When the user says:

• "This function throws an error when passed null"
• "The page crashes on mobile devices"
• "Users report checkout fails intermittently"
• "Fix the memory leak in the background worker"
• "Debug why tests are failing on CI"

Debugging Techniques

Add logging:

console.log('Value at checkpoint:', value)
logger.debug('Processing item', { id: item.id, status: item.status })

Use debugger:

debugger;  // Browser will pause here

Binary search:

• Comment out half the code
• If bug disappears, it's in that half
• Repeat until isolated

Compare working vs broken:

• What changed between working and broken?
• Git bisect to find breaking commit
• Compare with known-good version

Output Format

After fixing:

## Bug Fix: [Brief description]

### Issue
[What was broken and how it manifested]

### Root Cause
[Why the bug existed]

### Fix
[What was changed and why it fixes the issue]

### Verification
[Evidence the fix works - use proof-of-work skill]
- Original issue no longer reproduces
- Tests pass (include test output)
- Related scenarios still work

### Prevention
[What test was added to prevent regression]

Notes

• Use TodoWrite to track debugging steps
• Document findings even if you don't find the root cause immediately
• Use proof-of-work skill to show the bug is actually fixed
• Consider using boy-scout-rule skill to improve surrounding code
• Add test to prevent regression (use test-driven-development skill)