how to exit?

[Stefan Israelsson Tampe]

Ok, say that one want to execute a scheme function, f,  in a child process
and then exit, somthing like this is used in scsh,


first fork and if in chile

(f)
(exit 0)
------------------

Now cause we are in dubug context in the repl, we get this

Throw to key `quit' with args `(0)'.
Entering a new prompt.  Type `,bt' for a backtrace or `,q' to continue.
scheme@(guile-user) [1]> 

E.g. It handles the exit as an error. The setup has a list of pass-through
keys that, I think, is basicall '(quit). But issue (quit) does not work as 
well. So probably the debug context does not follow that key's suggestion.
So this is sort of a show stopper, how to fix this?

note:
if I add an if in the error-handler(on-trap debug) to follow the pass-keys? 
This works but there might be some bad side effects :-)

Also, I get
Some deprecated features have been used.  Set the environment
variable GUILE_WARN_DEPRECATED to "detailed" and rerun the
program to get more information.  Set it to "no" to suppress
this message.

trying
(setenv "GUILE_WARN_DEPRECATED" "detailed")

Does not work, I need to set it in the shell before starting guile
is this how it should work?

Regards
Stefan