Reproducing issue in Earthquakes app when one of operations does not transition from .Ready to .Executing state.

AppDelegate.swift

import UIKit

let sharedQueue = OperationQueue()

class TestOperation : Operation
{
    
    override func execute() {
        dispatch_async(dispatch_get_main_queue()) {
//            print("Finished.")
            self.finish()
        }
    }
    
}

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {
    // MARK: Properties

    var window: UIWindow?
    
    func applicationDidFinishLaunching(application: UIApplication) {
        cycle(1)
    }
    
    func cycle(take: Int)
    {
        var operations = [Operation]()
        
        let startOp = BlockOperation {
            print("Begin operations: Take \(take)")
        }
        
        let endOp = BlockOperation { [weak self] in
            print("End operations")
            
            if take < 10 {
                self?.cycle(take + 1)
            }
            else {
                print("This is it!")
            }
        }
        
        for _ in 1...40
        {
            let op = TestOperation()
            
            op.addDependency(startOp)
            
            endOp.addDependency(op)
            
            operations.append(op)
        }
        
        operations.append(startOp)
        operations.append(endOp)
        
        sharedQueue.addOperations(operations, waitUntilFinished: false)
    }
    
    // MARK: UIApplicationDelegate

    func application(application: UIApplication, didFailToRegisterForRemoteNotificationsWithError error: NSError) {
        RemoteNotificationCondition.didFailToRegister(error)
    }
    
    func application(application: UIApplication, didRegisterForRemoteNotificationsWithDeviceToken deviceToken: NSData) {
        RemoteNotificationCondition.didReceiveNotificationToken(deviceToken)
    }
}

Sample project based on Advanced NSOperations:

https://dl.dropboxusercontent.com/u/546085/AdvancedNSOperationsCRASH.zip