I am getting an error while trying to install macaca to inspect elements in iOS app using Appium 1.6.4

>> xctest-client start with port: 8900

WebDriverAgent version: 1.1.6 app-inspector:66:44 [master] pid:5022 undefined (node:5022) UnhandledPromiseRejectionWarning: Unhandled promise rejection (rejection id: 1): Error: >> app-inspector:66:44 [master] pid:5022 undefined

Above is the error I get. Any solution or way to get it installed. Are there any other option to inspect elements for iOS app .