In the devel branch's util.Serializer there is a comment for the indexClasses function that (as far as I can interpret) states that a namespace is expected to be a JavaScript object:
/**
* Find and index all classes that appear as members of the namespace (a JavaScript Object)
*/
Can you please provide some kind of documentation that give hints of how a namespace object should look like? Since the Serializer is never used somewhere in the whole project I cannot infer anything and thus not test this function.