How can I get more verbose debugging information from hammerhead?

I am running into an issue where my web code is invoking an ajax call to another endpoint on the same server that is not completing. I can see in the server logs that the request is processed and the response is sent, but the network tool shows the response as not finished (stalled) even after several minutes.

I am looking for more details on what is happening in the proxy (perhaps it is waiting on more data from the server, etc). But I cannot find any logging from the proxy to assist in debugging.

EDIT: I have noticed this happens on all proxy requests with isXhr set.