Keeps returning (lldb)

import UIKit

class ViewController: UIViewController {

    private let apiKey = "473e1dc798554413fd594d6af03d7b01"

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.

        let baseURL = NSURL(string: "https://api.forecast.io/forecast/\(apiKey)/")
        let forecastURL = NSURL(string: "-15.733288,-47.874101", relativeToURL: baseURL)

        let sharedSession = NSURLSession.sharedSession()
        let downloadTask: NSURLSessionDownloadTask = sharedSession.downloadTaskWithURL(forecastURL!, completionHandler: { (#location: NSURL!, #response: NSURLResponse!, #error: NSError!) -> Void in

            if (error == nil){
            let dataObject = NSData(contentsOfURL: location)
            let weatherDictionary: NSDictionary = NSJSONSerialization.JSONObjectWithData(dataObject!, options: nil, error: nil) as NSDictionary
                println(weatherDictionary)
            }

        })
        downloadTask.resume()
    }
    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }


}