What problem does it solve? When a bug, error, crash, or failing test is reported, it is tempting to jump straight to a fix based on the error message alone. This Skill enforces a disciplined, evidence-driven investigation that reproduces the bug first, identifies the true root cause, and delivers a minimal verified fix instead of a speculative patch. ## Core Features & Use Cases - Seven-phase investigation procedure: Understand the problem, reproduce, gather scoped evidence, form ranked hypotheses, test them within a three-cycle budget, confirm the root cause, then fix with a regression test, code review, and fresh verification. - Hard gates and budgets: No fix without reproduction and an identified root cause, a five-file refocus rule to stop evidence spirals, and a three-cycle investigation budget before asking the user for direction. - Explicit return states: Every run ends as Fixed, Escalated to design, Non-reproducible, or Budget exhausted, so an unresolved bug is never silently claimed as fixed. - Use Case: A user reports that a checkout endpoint intermittently returns null. The Skill reproduces the failure, traces it to an enum change in a recent commit, gets the fix approach approved, writes a failing regression test, applies the minimal fix, and verifies the full suite passes. ## Quick Start Use the debug-investigation skill to investigate this failing test and find its root cause before changing any code.
