systematic-debugginglisted

# Systematic 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. **Violating the letter of this process is violating the spirit of debugging.** ## The Iron Law ``` NO FIXES WITHOUT ROOT CAUSE INVESTIGATION FIRST ``` If you haven't completed Phase 1, you cannot propose fixes. ## When to Use Use for ANY technical issue: - Test failures - Bugs in production - Unexpected behavior - Performance problems - Build failures - Integration issues **Use this ESPECIALLY when:** - Under time pressure (emergencies make guessing tempting) - "Just one quick fix" seems obvious - You've already tried multiple fixes - Previous fix didn't work - You don't fully understand the issue **Don't skip when:** - Issue seems simple (simple bugs have root causes too) - You're in a hurry (rushing guarantees rework) - Manager wants it fixed NOW (systematic is faster than thrashing) ## The Four Phases The order matters — a fix built before the cause is understood is a guess wearing a diff. Where a phase genuinely doesn't apply, say which one you skipped and why. (2026-07-28: this was "You MUST complete each phase before proceeding to the next." A no-guidance Opus 5 control, given a confident-but-wrong colleague diagnosis, a one-hour demo deadline and "it's a trivial one-liner", refused the fix, disproved the diagnosis from the snippet, went to root c