What problem does it solve? Hard bugs and flaky failures resist casual code reading; without a reproducible signal, debugging devolves into guessing. This Skill enforces a disciplined diagnosis loop that builds a tight pass/fail feedback signal first, then reproduces, minimizes, hypothesizes, instruments, fixes, and cleans up. ## Core Features & Use Cases - Feedback loop construction: Builds a red-capable, deterministic, fast reproduction command using failing tests, curl scripts, CLI fixtures, headless browsers, trace replay, fuzz loops, or bisection 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 and post-mortem: Writes the regression test before the fix at a correct seam, removes all debug instrumentation, and records the confirmed root cause in the commit message. - Use Case: A user reports that the export button intermittently throws an error in production. The Skill guides building a replay loop from a captured request, minimizing the failing scenario, testing ranked hypotheses, and landing a fix with a regression test. ## Quick Start Diagnose why the export endpoint intermittently returns a 500 error by building a reproduction loop and following the phased debugging workflow.
