[gambit-list] Debugging problem

David Rush kumoyuki at gmail.com
Sun Jan 18 16:08:33 EST 2009

2009/1/18 Christian Jaeger <christian at pflanze.mine.nu>:
> David Rush wrote:
>> So I've recently been bringing some old code up to speed on current
>> Gambit (4.4.0) and I seem to be running afoul of some combination of
>> the REPL changes and the debugger that have me totally blocked.
>> When I run the compiled version of the program, I get the *no* output
>> from the program and the following:
>> *** ERROR IN call-with-values -- (Argument 2) LIST expected
>> (apply '#<procedure #2> '#<unknown>)
> Without seeing the code or a stripped-down version of it it's difficult
> to tell.

Well it's 22KLOC and moderately inbred with heavy use of an unholy
hybrid of call/cc and call-with-values to implement a wacky
tail-recursive pattern matcher. Oh yeah, and lots of anonymous
functions. This is really more a question about how the debug REPL
works (or fails to).

>> What's going on here? And how can I get to the debugger to try and
>> find the culprit call-with-values?
> - put (step) at some good place before the problematic part into your code

I have no idea where that is. This is why I'm trying to get a
backtrace from the actual error location.

> - if your program can afford it memory-wise, try
> (generate-proper-tail-calls #f)

That is an option I'd forgotten. Will it help (as in get me a stack
dump) with the compiled code? After further testing, the problem
appears to simply not arise under the interpreter.

> If you've got difficulties finding the right spot in your program, you
> can also capture continuations while the program is running and use them
> to go back once you got the exception;

This (now) is essentially the problem. I don't get an exception
running under the REPL. I'd like to get a stack dump while running
compiled, actually

david rush
GPG Public key at http://cyber-rush.org/drr/gpg-public-key.txt

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