Learned how to turn on Gather coverage in Xcode. I always forget where this should be turned on.

Do you know expandingTildeInPath exists for NSString but not for String. URL has standardizedFileURL but it isn’t doing what you would expect. The easiest way fill gap - bridge to NSString:

let expandedPath = (CommandLine.arguments[1] as NSString).expandingTildeInPath
let url = URL(fileURLWithPath: expandedPath)

TODO: add here explanation of what is standardizedFileURL really doing. And use NSString initializer instead of cast.