What problem does it solve? Hard bugs and flaky performance regressions resist casual code reading; without a reproducible signal, debugging devolves into guessing. This Skill enforces a disciplined six-phase diagnosis loop that builds a tight pass/fail feedback signal before any hypothesis is tested. ## Core Features & Use Cases - Feedback Loop Construction: Builds a red-capable, deterministic, fast repro command using failing tests, curl scripts, headless browser runs, trace replay, fuzz loops, or git bisect harnesses. - Structured Hypothesis Testing: Generates 3-5 ranked falsifiable hypotheses, then instruments with tagged debug logs or debugger breakpoints, changing one variable at a time. - Regression Lockdown: Writes the regression test before the fix at a correct seam, then cleans up all debug instrumentation and documents the confirmed root cause. - Use Case: A user reports the export button intermittently throws an error. The Skill drives creation of a deterministic repro script, minimises the failing scenario, tests ranked hypotheses, applies the fix, and leaves a regression test behind. ## Quick Start Diagnose this bug: the export button throws an error intermittently, build a feedback loop and find the root cause.
