The Xcode project wired macos/RunnerTests/MpvMetalLayerTests.swift into
the RunnerTests target, but the file was never committed alongside it,
so the macOS test target failed to build from a clean checkout:
error: Build input file cannot be found: .../MpvMetalLayerTests.swift
(in target 'RunnerTests' from project 'Runner')
Remove the reference. The test it belonged to is parked on
wip/macos-drawable-size-sync together with the change it covers.
edde746
bae6055123