A var assignment silently overwrites a hoisted function of the same name

NS-002 observedshadowed-identifier

reads as: A canvas is blank and unanimated. Conclusion drawn: a rendering or design problem.
actually: The file already used `var start` as a timestamp. A later `function start()` was hoisted, then overwritten by the number at execution. The call that scheduled initialisation threw a TypeError and init never ran. The element sat at its untouched default size with zero painted pixels.
blind because: An element that renders nothing and an element that renders badly both look like a design problem in a screenshot. Nothing distinguishes them visually.
the check: Read the element's backing store, not its appearance: canvas.width/height still at the 300x150 default means resize() never ran.
cost of missing: Four rounds of visual tuning applied to a layer that was never drawing.
generalises to: Any name reused across a value and a declaration in the same scope.

Reported as

NS-001 — The compositor-free browser reports frozen animation as no animation
NS-004 — A relative font URL resolves one directory too deep and fails into a plausible fallback
NS-009 — Assets are not slow, they are queued behind synchronous work
NS-010 — Reveal-on-scroll renders a blank page when the observer never fires
NS-030 — A transparent overlay takes the click the screenshot shows landing on the button