Demonstrates NSURLSession's lack of localized error descriptions.

bad-error-messages

#!/usr/bin/swift

import Foundation

let url = NSURL(string: "http://not-a-real-host")!
let request = NSURLRequest(URL: url)

var response:NSURLResponse? = nil
var error:NSError? = nil
NSURLConnection.sendSynchronousRequest(request, returningResponse: &response, error: &error)

println("Good error \(error!.code) from NSURLConnection: \(error!.localizedDescription)")

let data = "hello".dataUsingEncoding(NSUTF8StringEncoding, allowLossyConversion: false)
let task = NSURLSession.sharedSession().uploadTaskWithRequest(request, fromData: data)
task.resume()
while task.state != .Completed {
    usleep(1)
}

println("Bad error \(task.error!.code) from NSURLSession: \(task.error!.localizedDescription)")