[slime-devel] Hints needed on why "Process inferior-lisp hangup" occurs

[Helmut Eller]

* Willem Rein Oudshoorn [2009-06-01 15:52+0200] writes:

> I need some hints to start figuring out why I regularly get a 
> "Process inferior-lisp hangup" in my *inferior-lisp* buffer, but I do 
> not have clue where to start. 
>
> Situation:
>
> * OS:            Mac OS X 
> * Lisp version:  sbcl 64bit 1.0.28  and  ccl 1.3-r12156M  (64bit)
> * Slime version:  CVS version as of today.
>
> "Reproduction Scenario"
>
> 1 Start slime with one of the two lisp implementaitons mentioned above
> 2 Open "/dev/tty.NXT-DevB-1", which is a serial blue tooth connection
>   to a Lego NXT brick.
> 3 Turn of the Lego NXT brick (the other side of the serial connection)

Fancy toys.

> After this, I get the "Process inferior-lisp hangup" in the
> *inferior-lisp* buffer.
>
> In contrast, if I do not run this through slime, but just run it from a
> terminal the lisp implementaiton is not killed.  
>
> I assume that the serial bluetooth connection is closed from the other
> side and that that somehow closes also the slime connection.  But
> I don't know why, if this is normal, and how to change this behaviour.
>
> All hints are appreciated.

To me it looks like the subprocess receives a SIGHUP when the serial
connection goes down.  At least http://en.wikipedia.org/wiki/SIGHUP
mentions that as the historical usage of SIGHUP.

Perhaps it helps if you install a signal handler for SIGHUP to ignore
it.  It might also help to bind process-connection-type in
slime-start-lisp to 'pty instead of nil.

Helmut.