Undefined symbols for architecture armv7:
  "_OBJC_CLASS_$_FBSDKAccessToken", referenced from:
      objc-class-ref in libextension_facebook.a(b4c8e058_FacebookObserver.o)
  "_OBJC_CLASS_$_FBSDKGameRequestDialog", referenced from:
      objc-class-ref in libextension_facebook.a(b4c8e058_Facebook.o)
  "_OBJC_CLASS_$_FBSDKShareDialog", referenced from:
      objc-class-ref in libextension_facebook.a(b4c8e058_Facebook.o)
  "_FBSDKAccessTokenDidChangeNotification", referenced from:
      extension_facebook::init() in libextension_facebook.a(b4c8e058_Facebook.o)
  "_OBJC_CLASS_$_FBSDKAppEvents", referenced from:
      objc-class-ref in libextension_facebook.a(b4c8e058_Facebook.o)
      objc-class-ref in libextension_facebook.a(b4c8e058_FacebookObserver.o)
  "_OBJC_CLASS_$_FBSDKAppInviteDialog", referenced from:
      objc-class-ref in libextension_facebook.a(b4c8e058_Facebook.o)
  "_OBJC_CLASS_$_Enhance", referenced from:
      objc-class-ref in libenhance.a(d9451189_Enhance.o)
  "_OBJC_CLASS_$_FBSDKGameRequestContent", referenced from:
      objc-class-ref in libextension_facebook.a(b4c8e058_Facebook.o)
  "_OBJC_CLASS_$_FBSDKLoginManager", referenced from:
      objc-class-ref in libextension_facebook.a(b4c8e058_Facebook.o)
  "_OBJC_CLASS_$_FBSDKShareLinkContent", referenced from:
      objc-class-ref in libextension_facebook.a(b4c8e058_Facebook.o)
  "_OBJC_CLASS_$_FBSDKAppInviteContent", referenced from:
      objc-class-ref in libextension_facebook.a(b4c8e058_Facebook.o)
  "_OBJC_CLASS_$_FBSDKApplicationDelegate", referenced from:
      objc-class-ref in libextension_facebook.a(b4c8e058_Facebook.o)
      objc-class-ref in libextension_facebook.a(b4c8e058_CallbacksDelegate.o)
      objc-class-ref in libextension_facebook.a(b4c8e058_FacebookObserver.o)
ld: symbol(s) not found for architecture armv7
clang: error: linker command failed with exit code 1 (use -v to see invocation)