The API reference says that proxy-display has no writer and that
define-request refuses, as it is expanded, a request it cannot define.
The scanner's page calls shipped-protocols and shipped-array-elements in
place of the old variables, and names the new cases of protocol-error.
The errors page lists the new wl-error cases, among them an array event
of the wrong length and misuse of the test compositor, whose page says
so too. The internals page describes the read step that dispatch and
read-events share. Home's example gives every package a local
nickname, as the README's does, and Getting Started recommends that.