Bugfix and Debug Skill | Agent Skills

Bugfix and Debug

Exclusive to: debugger agent

MCP Helpers (Brain + Memory)

🧠 Gemini-Bridge (Brain) — Deep Error Analysis

mcp_gemini-bridge_consult_gemini(query="Root cause analysis: [error message]. Stack trace: [trace]", directory=".")

🌉 Open-Bridge — Alternative Error Analysis

mcp_open-bridge_consult_gemini(query="Root cause analysis: [error message]. Stack trace: [trace]", directory=".")

📚 Context7 (Memory) — Up-to-Date Docs

Lookup error patterns and fixes in official docs:

mcp_context7_resolve-library-id(libraryName="[library]", query="[error type]")
mcp_context7_query-docs(libraryId="/[resolved-id]", query="[specific error message]")

Validation Loop (MANDATORY)

Before completing any fix, run this verification sequence:

composer test            # All PHP tests pass
npm run types           # No TypeScript errors
npm run lint            # No linting errors

If any command fails, investigate and fix before reporting completion.

Instructions

Phase 1: Evidence Collection

Capture exact error message and stack trace
Identify reproduction steps (command + inputs)
Note when it started (recent changes?)
Check logs: storage/logs/laravel.log

Phase 2: Hypothesis Formation

Form 1-3 ranked hypotheses based on:

Error message keywords
Stack trace file paths
Recent git changes
Similar past issues

Phase 3: Verification

# Search for error patterns
grep -r "error text" --include="*.php" --include="*.tsx" app/ resources/

# Check recent changes
git log --oneline -10
git diff HEAD~3

# Run isolated test
php artisan test --filter=TestName

Phase 4: Minimal Fix

Fix root cause, not symptoms
Make smallest change possible
Consider related edge cases

Phase 5: Regression Prevention

Add/update test covering the fixed case
Verify test fails without fix, passes with fix

Common Laravel Error Patterns

| Error | Likely Cause | Solution | |-------|-------------|----------| | ModelNotFoundException | Wrong ID, missing record | Check route model binding | | ValidationException | Invalid input | Review FormRequest rules | | AuthorizationException | Policy failure | Check policy methods | | QueryException | SQL error | Check migration/schema | | TokenMismatchException | CSRF issue | Add @csrf directive | | Class not found | Autoload issue | Run composer dump-autoload |

Common React/TypeScript Errors

| Error | Likely Cause | Solution | |-------|-------------|----------| | Cannot read property of undefined | Null access | Add optional chaining ?. | | Type 'X' is not assignable | Type mismatch | Fix interface/props | | Hook call violation | Hook in wrong place | Move to component | | Hydration mismatch | SSR/client diff | Use useEffect |

Debugging Commands

# Laravel
php artisan tinker                    # Interactive REPL
tail -f storage/logs/laravel.log     # Watch logs
php artisan route:list               # Check routes
php artisan migrate:status           # Check migrations

# Frontend
npm run types                        # TypeScript errors
npm run lint                         # ESLint issues

Output Template

## 🐛 Bug
[One sentence description]

## 🔍 Root Cause
[What was wrong and why]

## 🔧 Fix
| File | Change |
|------|--------|
| `path/file` | Description |

## 🧪 Regression Test
[Test name and coverage]

## ✅ Verification
$ [command]
[output]

Examples

"Fix this failing Pest test"
"Users can't log in; find why and patch it safely"
"Debug why form submission fails with 500 error"

Agent Skills: Bugfix and Debug

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