Bug Root Cause Tracing

Overview

Bugs often manifest deep in the call stack — wrong directory, bad parameter, corrupted data — far from where the invalid value originated. Fixing where the error appears treats the symptom. Tracing backward to find the original trigger fixes the cause.

Core principle: Never fix where the error surfaces. Trace back until you find what actually caused it.

For coding-related work, load engineering-principles before this skill. Root cause tracing applies its fail-fast, explicit-state, and boundary principles to the path that introduced bad state.