Debugging Skill
Systematic debugging, root cause analysis, and error investigation.
When to Use
- •Investigating errors or bugs
- •Diagnosing unexpected behavior
- •Performance issues
- •Production incidents
- •User says "debug", "error", "why is this broken", "not working"
Debugging Approach
1. Understand the Problem
- •What is expected vs actual behavior?
- •When did it start? Can it be reproduced?
- •What changed recently?
2. Gather Evidence
- •Read logs and stack traces
- •Review recent changes
- •Identify patterns
3. Form Hypothesis
- •What is the most likely cause?
- •What evidence supports this?
4. Test Hypothesis
- •Design targeted test
- •Observe results
- •Refine if needed
5. Implement Fix
- •Develop minimal fix
- •Verify resolution
- •Add regression tests
6. Document
- •Root cause and fix
- •Add monitoring/alerting
Issue Categories
- •Logic Errors: Incorrect conditions, off-by-one, wrong operators
- •State Errors: Race conditions, stale closures, shared mutable state
- •Integration Errors: API mismatch, auth issues, timeouts
- •Performance: N+1 queries, missing indexes, memory leaks
- •Environment: Config differences, missing vars, permissions
Systematic Process
Follow the six-step debugging process with:
- •Checklists for investigation and evidence gathering
- •Severity levels (CRITICAL, HIGH, MEDIUM, LOW)
- •Output templates for documentation
- •Tools by environment (browser, Node.js, database)
See refs/process.md for detailed process, checklists, and severity guidelines.
Common Patterns
Debugging techniques and solutions for:
- •Null/undefined issues with optional chaining
- •Async timing and race conditions
- •Scope and closure problems
- •Binary search debugging with git bisect
- •Performance profiling
- •Database query analysis
See refs/patterns.md for code examples and debugging techniques.
External Integration Discovery
Debugging can leverage available integrations by capability:
| Capability | Discovery Patterns | Provides |
|---|---|---|
| Error tracking | sentry, rollbar, datadog | Recent errors, stack traces, user context |
| Observability | newrelic, dynatrace, telemetry | APM data, traces, metrics |
| Logging | splunk, elastic, cloudwatch | Log aggregation, search |
Run ListMcpResourcesTool to discover available integrations. Fall back to local log analysis via wicked-search when none available.
Notes
- •Start with the simplest explanation
- •Use scientific method: hypothesis, test, refine
- •Document your findings for future reference
- •Add tests to prevent regression