This is a swift port of the official FacebookSDK login tutorial. It's been tested on Xcode 6 Beta 1 with the iOS 8 Simulator. You can find the official FB tutorial here: https://developers.facebook.com/docs/facebook-login/ios/v2.0

FBLogin.swift

// YourProject-Bridging-Header.h
#import <FacebookSDK/FacebookSDK.h>


// AppDelegate.swift
import UIKit
 
@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {
    .
    .
    .
    func application(application: UIApplication, openURL url: NSURL, sourceApplication: NSString?, annotation: AnyObject) -> Bool {
        var wasHandled:Bool = FBAppCall.handleOpenURL(url, sourceApplication: sourceApplication)
        return wasHandled
    }
 
}

// ViewController.swift
import Foundation
import UIKit

class LoginViewController: UIViewController, FBLoginViewDelegate {
    
    var fbl: FBLoginView = FBLoginView()
    
    @IBOutlet var loginView : FBLoginView
    @IBOutlet var profilePictureView : FBProfilePictureView
    @IBOutlet var userNameTxt : UILabel
    @IBOutlet var logStatusTxt : UILabel
    
    override func viewDidLoad() {
        super.viewDidLoad()
        fbl.delegate = self
        loginView.readPermissions = ["public_profile", "email", "user_friends"]
        // Do any additional setup after loading the view, typically from a nib.
    }
    
    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
    
    func loginViewShowingLoggedInUser(loginView: FBLoginView) {
        logStatusTxt.text = "You are logged in!"
    }
    
    func loginViewFetchedUserInfo(loginView: FBLoginView?, user: FBGraphUser) {
            profilePictureView.profileID = user.objectID
            userNameTxt.text = user.first_name + " " + user.last_name
    }
    
    func loginViewShowingLoggedOutUser(loginView: FBLoginView?) {
        profilePictureView.profileID = nil
        userNameTxt.text = ""
        logStatusTxt.text = "You are logged out!"
    }
}

This code crashes on Xcode 6 Beta 3, but works fine on Beta 2.

Relevant stack trace:

1.  While type-checking 'APIController' at /Users/bagvendt/projects/locy-swift/locy-swift/APIController.swift:30:1
2.  While resolving type FBGraphUser at [/Users/bagvendt/projects/locy-swift/locy-swift/APIController.swift:168:45 - line:168:45] RangeText="F"
<unknown>:0: error: unable to execute command: Segmentation fault: 11

FINALLY someone with the same problem haha.
I tested on xcode beta 1 and 3, same problem. Downloading beta 2 now...

I don't get the same error on Xcode6, however, the app will stop running with:
dyld: lazy symbol binding failed: Symbol not found: __TFSsg3nilVSs4_Nil

Same issue. Originally worked fine with beta 2, doesn't work with beta 3. Tried reopening in beta 2 and got different errors. Beta 3 must of made changes and now i can't go back :(

@pocketkk Exact issue here. I've already submitted a bug report to apple...

This guide helped me a lot. But when I want to declare the delegate of Facebook in UIViewController no longer compiles and Xcode (beta 3) begins to fail with the following warning: SourceKitService Terminated

It's so sad :(

Can you guys help me to test if this is working on Beta 4? I think it is.

In this code, I don't understand why you have to declare
var fbl: FBLoginView = FBLoginView()
and the
fbl.delegate = self
is then not needed.
I would have set the
loginView.delegate = self
instead

and in the AppDelegate.swift
func application(application: UIApplication!, didFinishLaunchingWithOptions launchOptions: NSDictionary!) -> Bool {
// Override point for customization after application launch.
FBLoginView.self()
return true
}

@iaserrat, checked, works in Beta4

It works on beta 4!