Function resolveDockerHostPlatform

packages/cli/src/commands/render.ts:1200–1233

* Resolves the Docker `--platform` for this host and enforces the constraints * that come with it — keeping that policy out of `renderDocker` so the * orchestrator stays focused on build/run wiring. May terminate the process * via errorBox on unrecoverable mismatches (e.g. --gpu on arm64).

(options: RenderOptions)

 * via errorBox on unrecoverable mismatches (e.g. --gpu on arm64).
 */
function resolveDockerHostPlatform(options: RenderOptions): string {
  const platform = resolveDockerPlatform();

  // Docker Desktop on Apple Silicon (and colima with VZ) doesn't implement
  // the `--gpus` host-passthrough flag, so requesting `--gpu` on a linux/arm64
  // container fails at `docker run` with an opaque device-driver error. Catch
  // it early with actionable guidance.
  if (options.gpu && platform === "linux/arm64") {
    errorBox(
      "--gpu is not supported with --docker on arm64 hosts",
      "Docker Desktop/colima on Apple Silicon doesn't expose --gpus host passthrough to linux/arm64 containers.",
      "Drop --gpu, or run a native (non-Docker) render on this host, or set HYPERFRAMES_DOCKER_PLATFORM=linux/amd64 if you need GPU encoding (slow under qemu but works).",
    );
    process.exit(1);
  }

  if (!options.quiet && platform === "linux/arm64") {
    // chrome-headless-shell doesn't publish a linux-arm64 build, so the arm64
    // image falls back to system chromium. That loses byte-for-byte parity
    // with amd64 renders — fine for end-user output, not fine if you're
    // comparing against an amd64 golden baseline. Set
    // HYPERFRAMES_DOCKER_PLATFORM=linux/amd64 to keep parity (qemu-emulated,
    // slower).
    console.log(
      c.dim(
        "  Host is arm64 — using linux/arm64 image with system chromium " +
          "(output won't be byte-identical to amd64 renders; " +
          "set HYPERFRAMES_DOCKER_PLATFORM=linux/amd64 to force parity).",
      ),
    );
  }

  return platform;
}

// Inherited minor finding (CRAP 37.1, cyclomatic 11). This PR only added
// `pageNavigationTimeoutMs` to the options forwarded to `buildDockerRunArgs`.