rnd-debugginglisted

# R&D Debugging ## Overview Random fixes waste time and create new bugs. Quick patches mask underlying issues. **Core principle:** ALWAYS find root cause before attempting fixes. Symptom fixes are failure. ## When to Use - Any test failure during build or verification phases - Unexpected behavior during integration - Bugs found by the Verifier's failure mode analysis - Performance issues discovered during system validation ## The Iron Law ``` NO FIXES WITHOUT ROOT CAUSE INVESTIGATION FIRST ``` If you haven't completed Phase 1, you cannot propose fixes. ## The Four Phases ### Phase 1: Root Cause Investigation BEFORE attempting ANY fix: 1. **Read error messages carefully** — Stack traces, line numbers, error codes. Don't skip. 2. **Reproduce consistently** — Can you trigger it reliably? What are the exact steps? 3. **Check recent changes** — Git diff, recent commits, new dependencies 4. **Trace data flow** — Where does the bad value originate? Trace backward through the call stack. 5. **Gather evidence in multi-component systems** — Log what enters/exits each component boundary. Run once to see WHERE it breaks. ### Phase 2: Pattern Analysis 1. **Find working examples** — Similar working code in the same codebase 2. **Compare against references** — Read reference implementations COMPLETELY 3. **Identify differences** — List every difference, however small 4. **Understand dependencies** — What settings, config, environment does this need? ### Phase 3: Hypothesis an