What problem does it solve? Hard bugs and 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, red-capable feedback loop before any hypothesis is tested. ## Core Features & Use Cases - Feedback Loop Construction: Builds a deterministic pass/fail signal via failing tests, curl scripts, CLI invocations, headless browser scripts, trace replay, fuzz loops, or bisection harnesses. - Structured Hypothesis Testing: Generates 3-5 ranked, falsifiable hypotheses, then instruments with tagged debug logs or debugger probes, changing one variable at a time. - Regression Lockdown: Writes a regression test at a correct seam before the fix, then cleans up all debug instrumentation and throwaway prototypes. - Use Case: A user reports an intermittent export failure in production. The Skill guides building a replay harness from a captured request, minimising the repro, ranking hypotheses, and landing a fix with a regression test. ## Quick Start Ask the agent to diagnose the bug where the export button throws an error, and have it build a failing reproduction loop before proposing any fix.
