debugging-patterns

# Debugging Patterns ## Overview Provides structured frameworks for root cause analysis. The log-first methodology ensures evidence is gathered before hypotheses are formed. ## Log-First Investigation 1. Read ALL available logs, error output, and stack traces 2. DO NOT form hypotheses before reading evidence 3. Identify the exact error: message, file, line, call stack 4. Determine reproduction steps from evidence 5. Check git log for recent changes correlating with bug introduction ## Pattern-Based Diagnosis - Check patterns.md for known gotchas matching the error - Cross-reference with common patterns: null pointer, race condition, resource leak, config error - Rate root cause confidence (>=80% to proceed with fix) ## Evidence Collection - Stack traces with full call chain - Error messages with context - Exit codes from reproduction attempts - Git blame/log for change correlation - Environment differences (if applicable) ## When to Use - During DEBUG workflow investigation phase - When BUILD tests fail unexpectedly - When reviewing error handling gaps ## Agents Used - `bug-investigator` (primary consumer) - `silent-failure-hunter` (pattern reference)