Swank server dies with any error in REPL

Earl DuCaine earl.ducaine at gmail.com
Wed Sep 2 04:37:27 UTC 2015

Are you running ECL from the sh/bash shell in Emacs?  I've run into 
problems with that in ECL, it seems to point to some bug in slime but I 
haven't had a chance to investigate.  It could equally be something I'm 
doing wrong.  But try the following:

- Double check your .eclrc resource file and make sure that the only 
thing your loading is quicklisp.  (to remove as many troubleshooting 
variables as possible.)

- Run ECL from an ordinary terminal window and start swank.

- Connect to swank in Emacs using slime like you normally would.

If that ends up working, then one thing you could try is running two 
separate instance of Emacs, one for Swank and the other for connecting 
with Slime.  Oddly that resolved the problem for me.

On 09/01/2015 08:22 AM, bruce li wrote:
> Thanks for the reply. But I don't quite understand what it means. I
> was doing something similar to
> https://chriskohlhepp.wordpress.com/embedding-lisp-in-cplusplus-a-recipe/
> . When I hit C-c in the console, I drop into the top-level REPL. I
> typed:
>> (swank:create-server :port 4005)
> ;; Swank started at port: 4005.
> Then I connect to swank server with SLIME, inside which I put
> something wrong there:
> CL-USER> asdf
> Debugger received error of type: UNBOUND-VARIABLE
> The variable ASDF; Evaluation aborted on #<a UNBOUND-VARIABLE>.
> After that, swank server stops. And I'm dropped back to top level. I
> wonder why this happens.
> Thanks,
> Bruce
> 2015-09-01 9:34 GMT-04:00 Daniel Kochmański <daniel-28Bxc6qBrvkO3tVf+UDk3w at public.gmane.org>:
>> Hello,
>> if you call lisp forms from C code (after cl_boot), then you have no set
>> handler, so if your code signals a condition, then it goes uncought. If
>> that's a case, you could do something, what toplevel does (setting
>> handlers etc), or set si::*break-level* to 1 and call tpl:
>> (let ((si::*break-level* 1)) (si::tpl))
>> this should spawn toplevel console and won't exit. If you want to set
>> proper handler consult src/lsp/tpl.lsp file in ECL sourcecode.
>> Regards,
>> Daniel
>> bruce li writes:
>>> Hi, there,
>>> I'm pretty new to ECL. I'm currently considering embedding ECL in a
>>> game engine. When I interactively interrupt the program and drop into
>>> the repl, I load up swank with quicklisp and create swank server with
>>> (swank:create-server :port 4005).  I can connect to it from SLIME. But
>>> any error in the statement, either by deliberately typing sth wrong,
>>> will cause swank server to close instead of dropping into the
>>> debugging environment. I have no idea why this happens. It turns out
>>> that if I start swank on a different thread with
>>> mp:process-run-function, it goes well. But since the game engine is
>>> based on OpenGL, multithreading rendering isn't an option. I wonder if
>>> there is any way to get around the swank server and enable its
>>> debugger when it encounters error.
>>> Thanks,
>>> Bruce
>> --
>> Daniel Kochmański | Poznań, Poland
>> ;; aka jackdaniel
>> "Be the change that you wish to see in the world." - Mahatma Gandhi

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