If set then we'll call this function every time a callback is generated. This is SLOW!! - it's for debugging - don't keep it on all the time. If you want to access a specific callback then please create an issue on github and I'll add it! Params are : [Callback Type] [Callback Contents] [server]

Called if an exception happens during a callback/callresult. This is needed because the exception isn't always accessible when running async.. and can fail silently. With this hooked you won't be stuck wondering what happened.