According to the documentation:

"Once a handler has completely processed a message, a response
containing a `:status` of `:done` must be sent."

I am assuming this includes messages that have resulted in an error. Some messages to an nREPL server never respond with such a status possibly leaving some clients waiting for follow up messages forever.

So far I have found two instances of this problem.

1. The interruptible-eval middleware may result in a :no-code error that does not include the :done status.

2. The session middleware may result in a :unknown-session error that does not include the :done status.

I'm including a patch for the above two which are just one word fixes. There might be other situations in which the problem arises.