在命令行运行 app-inspector -u YOUR-DEVICE-ID 报如下错误：

xctest-client start with port: 8900
WebDriverAgent version: 1.0.41
app-inspector:66:44 [master] pid:1660 undefined
(node:1660) UnhandledPromiseRejectionWarning: Unhandled promise rejection (rejection id: 1): Error: >> app-inspector:66:44 [master] pid:1660 undefined

求大神指教，这是什么错误引起的