The windows that is shown by spicy when no connection arguments are specified only handles network-based connections correctly. I am using a socket for communication and this socket also appears in the "Recent connections" list (even though it cannot be created using that GUI). However, it cannot be launched after selecting it, as the GUI tries to enforce having a host and a port. One can provide complete dummy values in the respective fields and afterwards the connection can be established correctly, but at least this validation step is nonsense. It would be nice if socket connections were supported consistently here.