What problem does it solve? When facing bugs, errors, test failures, or unexpected behavior, developers often guess at fixes by reading code statically, leading to wrong fixes and wasted time. This Skill enforces a systematic debugging loop where every conclusion is backed by runtime evidence—logs, stack traces, variable values, and test results—rather than speculation. ## Core Features & Use Cases - Evidence-Driven Debugging Loop: Executes a closed loop of information gathering, minimal reproduction, evidence collection, hypothesis-verify cycles, root-cause localization, minimal fix, and regression verification. - Bisection and Instrumentation: Uses git bisect, code disabling, and input halving to narrow scope, plus temporary DEBUG-TRACE instrumentation that is always cleaned up afterward. - Handoff Integration: Receives failure root-cause tasks from api-testing, e2e-testing, and demo-verify skills, and hands off impact analysis to bug-impact-analysis before or after fixes. - Use Case: A failing API test is handed over with its assertion output and logs; the Skill reproduces the failure minimally, instruments the suspicious path, falsifies hypotheses one by one, locates the root cause, applies a minimal fix, and verifies the reproduction case now passes. ## Quick Start Ask the AI to debug why this test is failing and locate the root cause with runtime evidence.