CI3 core code bug

CodeIgniter provides hooks, yes. *By design*, get_instance does *not* exist when "pre-system" hooks are called. That is the intent.

There is a "pre-controller" hook, which happens after all the core system classes have been instantiated, and at which point, *by specific design*, get_instance *does* exist.

If you want to write a hook that uses get_instance, shouldn't you be configuring it as a "pre-controller" hook.