exit 1
		;;
	esac
}

assert_is_supported_os() {
	case "${KNAME}" in
	Linux | FreeBSD | OpenBSD | NetBSD | DragonFly | SunOS)
		return
		;;
	Darwin)
		osx_host_version=$(env sw_vers -productVersion)
		if ! check_minimum_version "${OSX_VERSION}" "${osx_host_version}"; then

		case "darwin", "ios":
			// Copied from golang.org/x/sys/unix/dev_darwin.go.
			major := uint32((dev >> 24) & 0xff)
			minor := uint32(dev & 0xffffff)
			h.Devmajor, h.Devminor = int64(major), int64(minor)
		case "dragonfly":
			// Copied from golang.org/x/sys/unix/dev_dragonfly.go.
			major := uint32((dev >> 8) & 0xff)
			minor := uint32(dev & 0xffff00ff)
			h.Devmajor, h.Devminor = int64(major), int64(minor)
		case "freebsd":