ErrorGist.swift

// Swift 2.2
// Xcode Version 7.3 (7D175)

        // 1 
        do {
            try coordinator.addPersistentStoreWithType(NSSQLiteStoreType, configuration: nil, URL: url, options: nil)
        } catch {
            var dict = [String: AnyObject]()

            // Build warning:
            // Forced cast from 'ErrorType' to 'NSError' always succeeds; did you mean to use 'as'?
            dict[NSUnderlyingErrorKey] = error as! NSError

            let wrappedError = NSError(domain: "error-domain", code: 0001, userInfo: dict)
        }

        // 2
        do {
            try coordinator.addPersistentStoreWithType(NSSQLiteStoreType, configuration: nil, URL: url, options: nil)
        } catch {
            var dict = [String: AnyObject]()

            // Build error:
            // 'ErrorType' is not convertible to 'NSError'; did you mean to use 'as!' to force downcast?
            dict[NSUnderlyingErrorKey] = error as NSError

            let wrappedError = NSError(domain: "error-domain", code: 0001, userInfo: dict)
        }

Hi there, I run into this problem yesterday, but I cannot resolve it. I reinstall my Xcode, but with no lucky. Did you find out why?