Overview

Debugging Patterns provides structured frameworks for root cause analysis, prioritizing evidence collection before forming hypotheses. It includes log-first investigation, pattern-based diagnosis, and confidence-scored fixes.

How This Skill Works

It guides you to read all logs and evidence first, identify the exact error (message, file, line, call stack), and derive reproducible steps. It then uses pattern-based diagnosis with known patterns from patterns.md and a confidence threshold (>=80%) before applying a fix.

When to Use It

• During the DEBUG workflow investigation phase
• When BUILD tests fail unexpectedly
• When reviewing error handling gaps
• When correlating bugs with recent code changes using git blame/log
• When using pattern-based diagnosis to match known gotchas in patterns.md

Quick Start

1. Step 1: Read ALL available logs, error output, and stack traces
2. Step 2: DO NOT form hypotheses before reading evidence; identify the exact error
3. Step 3: Check git log for recent changes, consult patterns.md, and rate confidence (>=80%) before proceeding

Best Practices

• Read all logs, error output, and stack traces before forming hypotheses
• Do not form hypotheses before evidence; follow the log-first approach
• Cross-reference errors with patterns.md and known gotchas
• Rate root cause confidence and only proceed with fix if >= 80%
• Collect comprehensive evidence: stack traces, error messages, exit codes, git blame/log, environment differences

Example Use Cases

• Example 1: A null pointer exception in a service is traced with full stack trace and git blame identifies the recent change that introduced it.
• Example 2: A race condition surfaces through interleaved logs and nondeterministic failures, solved by reproducing steps and pattern checks.
• Example 3: A misconfigured deployment causes a config error, uncovered by comparing environment differences.
• Example 4: A resource leak is found by tracking exit codes and long-running processes across multiple reproductions.
• Example 5: A known gotcha is matched via patterns.md, guiding diagnosis and confirming the fix with the reference pattern.

Frequently Asked Questions