-// If the Xcode version is 5.02 or earlier, this must be set to "-fobjc-gc".
-// If the Xcode version is newer than that, this must be blank (and the
-// builds created will not work on 10.6.)
+// If the Xcode version is 5.02 or earlier, use these settings:
+// "10.4", "-fobjc-gc", "-no-fobjc-gc"
+// If the Xcode version is later than that, use these settings:
+// "10.6", "", ""
+// and the generate builds will only work on 10.6 or later.