Previous patch still included a TODO in the tests, updated patch in 
attachment...

What is the idiomatic way to ensure a socket is closed when it's no 
longer needed?  I looked for something like a “with-open-socket” 
form, but that doesn't seem to exist.  My workaround feels a little 
clumsy:

               (let ((dict (socket PF_INET SOCK_STREAM 0))
                     (addr (make-socket-address AF_INET 
INADDR_LOOPBACK 8628)))
                 (connect dict addr)
                 (display "DEFINE Guix\n" dict)
                 (let ((response (read-line dict)))
                   (close dict)
                   response)))

Thomas