What problem does it solve? Debugging often produces quick patches that silence symptoms while the real bug survives, accumulating fragile workarounds across the codebase. This Skill enforces a disciplined debugging methodology that traces every failure to its root cause before writing a fix. ## Core Features & Use Cases - Reproduce-First Discipline: Requires reproducing the bug before attempting a fix, since an unreproducible bug cannot be verified as fixed. - Root-Cause Tracing: Applies iterative "why" questioning to move past symptoms, and explicitly rejects nil-check guards that merely silence crashes. - Pattern-Wide Fixes: Greps for the same defective pattern across the codebase and fixes all instances, not just the reported one. - Restart-Bug Heuristic: Directs investigation toward stale persistent state (config files, caches, lock files, serialized state) when failures appear only after restarts. - Use Case: A crash disappears after adding a nil check, but reappears elsewhere. This Skill pushes you to find why the value was nil in the first place and fix the source. ## Quick Start Apply the fix-root-causes principle to debug this failing test and trace the error back to its actual source before changing any code.
