debugging-patternslisted

# Debugging Patterns Domain skill for structured investigation of bugs and unexpected behavior. ## Iron Law **ALWAYS FIND ROOT CAUSE BEFORE ATTEMPTING FIXES. Symptom fixes are failure.** A fix that doesn't address root cause creates a new bug later. Every. Single. Time. ## Four-Phase Investigation ### 1. Gather Evidence Collect before theorizing: ```bash # Error logs, stack traces, recent changes git log --oneline -10 git diff HEAD~3..HEAD --stat ``` - Read error messages and stack traces FULLY — don't skim - Check logs in chronological order around the failure - Note what changed recently (`git log`, `git diff`) - Reproduce the error — if you can't reproduce it, you can't verify the fix ### 2. Pattern Analysis Look for patterns in the evidence: - When does it fail vs succeed? (inputs, timing, environment) - What's different between working and broken states? - Is the error consistent or intermittent? - Use `Grep` to find similar patterns: error messages, function calls, data flows ### 3. Hypothesis Testing Form and test hypotheses systematically. Use TaskCreate for each hypothesis: ``` TaskCreate("Hypothesis 1: {theory}", "Confidence: High\nTest: {specific test}\nEvidence: {what points here}") TaskCreate("Hypothesis 2: {theory}", "Confidence: Medium\nTest: {specific test}\nEvidence: {what points here}") TaskCreate("Hypothesis 3: {theory}", "Confidence: Low\nTest: {specific test}\nEvidence: {what points here}") ``` | # | Hypothesis | Confidence | Test | Result