Apple mach-o linker error showing xcode 4 & # 8594; after upgrade 5

Question

I am trying to fix the errors below, they started appearing after I upgraded to Xcode 5. Any ideas for fixing this error. I looked in the build settings - the path to the library and it was not indicated there.

Undefined symbols for architecture armv7:
  "_GKPlayerAuthenticationDidChangeNotificationName", referenced from:
      -[DDGameKitHelper registerForLocalPlayerAuthChange] in DDGameKitHelper.o
  "_OBJC_CLASS_$_GKAchievementViewController", referenced from:
      objc-class-ref in DDGameKitHelper.o
  "_OBJC_CLASS_$_GKNotificationBanner", referenced from:
      objc-class-ref in GKAchievementHandler.o
      objc-class-ref in GKAchievementNotification.o
  "_OBJC_CLASS_$_GKLeaderboardViewController", referenced from:
      objc-class-ref in DDGameKitHelper.o
  "_OBJC_CLASS_$_GKAchievementDescription", referenced from:
      objc-class-ref in DDGameKitHelper.o
  "_OBJC_CLASS_$_GKAchievement", referenced from:
      objc-class-ref in DDGameKitHelper.o
     (maybe you meant: _OBJC_CLASS_$_GKAchievementNotification, _OBJC_CLASS_$_GKAchievementHandler )
  "_OBJC_CLASS_$_GKScore", referenced from:
      objc-class-ref in DDGameKitHelper.o
  "_OBJC_CLASS_$_GKLeaderboard", referenced from:
      objc-class-ref in DDGameKitHelper.o
  "_OBJC_CLASS_$_GKLocalPlayer", referenced from:
      objc-class-ref in DDGameKitHelper.o
ld: symbol(s) not found for architecture armv7
clang: error: linker command failed with exit code 1 (use -v to see invocation)