fd.kind = kindFile
	case "console":
		fd.kind = kindConsole
	case "pipe":
		fd.kind = kindPipe
	case "tcp", "tcp4", "tcp6",
		"udp", "udp4", "udp6",
		"ip", "ip4", "ip6",
		"unix", "unixgram", "unixpacket":
		fd.kind = kindNet
	default:
		return "", errors.New("internal error: unknown network type " + net)
	}
	fd.isFile = fd.kind != kindNet

	var err error
	if pollable {