Quando eu adiciono a biblioteca do Google Analytics, eu tenho esse aviso

Undefined symbols for architecture armv7:
  "_OBJC_CLASS_$_NSAttributeDescription", referenced from:
      objc-class-ref in libGoogleAnalytics.a(GAICoreDataUtil.o)
      objc-class-ref in libGoogleAnalytics_debug.a(GAICoreDataUtil.o)
  "_OBJC_CLASS_$_NSFetchRequest", referenced from:
      objc-class-ref in libGoogleAnalytics.a(GAIDataStore.o)
      objc-class-ref in libGoogleAnalytics_debug.a(GAIDataStore.o)
  "_NSSQLiteErrorDomain", referenced from:
      l003 in libGoogleAnalytics.a(GAIDataStore.o)

Por favor me ajude