debugging
Systematic debugging methodology with root cause analysis. Phases: investigate, hypothesize, validate, verify. Capabilities: backward call stack tracing, multi-layer validation, verification protocols, symptom analysis, regression prevention. Actions: debug, investigate, trace, analyze, validate, verify bugs. Keywords: debugging, root cause, bug fix, stack trace, error investigation, test failure, exception handling, breakpoint, logging, reproduce, isolate, regression, call stack, symptom vs cause, hypothesis testing, validation, verification protocol. Use when: encountering bugs, analyzing test failures, tracing unexpected behavior, investigating performance issues, preventing regressions, validating fixes before completion claims.
When & Why to Use This Skill
This Claude skill provides a systematic debugging framework that emphasizes root cause analysis over superficial fixes. It guides users through a structured four-phase process—investigate, hypothesize, validate, and verify—to resolve complex software issues, trace errors through call stacks, and implement defense-in-depth validation to prevent future regressions.
Use Cases
- Identifying the root cause of deep-seated errors by tracing invalid data backward through the call stack level-by-level.
- Systematically resolving intermittent test failures and CI/CD pipeline issues using a hypothesis-driven investigation methodology.
- Implementing multi-layer validation and environment guards (Defense-in-Depth) to ensure bugs are structurally impossible to replicate.
- Providing rigorous verification protocols to confirm fixes with fresh evidence and logs before claiming task completion.
- Analyzing unexpected application behavior or performance bottlenecks through structured symptom analysis and pattern matching.
| name | debugging |
|---|---|
| description | "Systematic debugging methodology with root cause analysis. Phases: investigate, hypothesize, validate, verify. Capabilities: backward call stack tracing, multi-layer validation, verification protocols, symptom analysis, regression prevention. Actions: debug, investigate, trace, analyze, validate, verify bugs. Keywords: debugging, root cause, bug fix, stack trace, error investigation, test failure, exception handling, breakpoint, logging, reproduce, isolate, regression, call stack, symptom vs cause, hypothesis testing, validation, verification protocol. Use when: encountering bugs, analyzing test failures, tracing unexpected behavior, investigating performance issues, preventing regressions, validating fixes before completion claims." |
| version | 3.0.0 |
| languages | all |
Debugging
Comprehensive debugging framework combining systematic investigation, root cause tracing, defense-in-depth validation, and verification protocols.
Core Principle
NO FIXES WITHOUT ROOT CAUSE INVESTIGATION FIRST
Random fixes waste time and create new bugs. Find the root cause, fix at source, validate at every layer, verify before claiming success.
When to Use
Always use for: Test failures, bugs, unexpected behavior, performance issues, build failures, integration problems, before claiming work complete
Especially when: Under time pressure, "quick fix" seems obvious, tried multiple fixes, don't fully understand issue, about to claim success
The Four Techniques
1. Systematic Debugging (references/systematic-debugging.md)
Four-phase framework ensuring proper investigation:
- Phase 1: Root Cause Investigation (read errors, reproduce, check changes, gather evidence)
- Phase 2: Pattern Analysis (find working examples, compare, identify differences)
- Phase 3: Hypothesis and Testing (form theory, test minimally, verify)
- Phase 4: Implementation (create test, fix once, verify)
Key rule: Complete each phase before proceeding. No fixes without Phase 1.
Load when: Any bug/issue requiring investigation and fix
2. Root Cause Tracing (references/root-cause-tracing.md)
Trace bugs backward through call stack to find original trigger.
Technique: When error appears deep in execution, trace backward level-by-level until finding source where invalid data originated. Fix at source, not at symptom.
Includes: scripts/find-polluter.sh for bisecting test pollution
Load when: Error deep in call stack, unclear where invalid data originated
3. Defense-in-Depth (references/defense-in-depth.md)
Validate at every layer data passes through. Make bugs impossible.
Four layers: Entry validation → Business logic → Environment guards → Debug instrumentation
Load when: After finding root cause, need to add comprehensive validation
4. Verification (references/verification.md)
Run verification commands and confirm output before claiming success.
Iron law: NO COMPLETION CLAIMS WITHOUT FRESH VERIFICATION EVIDENCE
Run the command. Read the output. Then claim the result.
Load when: About to claim work complete, fixed, or passing
Quick Reference
Bug → systematic-debugging.md (Phase 1-4)
Error deep in stack? → root-cause-tracing.md (trace backward)
Found root cause? → defense-in-depth.md (add layers)
About to claim success? → verification.md (verify first)
Red Flags
Stop and follow process if thinking:
- "Quick fix for now, investigate later"
- "Just try changing X and see if it works"
- "It's probably X, let me fix that"
- "Should work now" / "Seems fixed"
- "Tests pass, we're done"
All mean: Return to systematic process.