Re: Sanitizer of record fields?

[Maxime Devos]

On 08-09-2022 13:35, bokr@bokr.com wrote:
> Hi Simon, et al
>
> On +2022-09-08 09:59:15 +0200, zimoun wrote:
> > Hi,
> >
> > The website is currently failing [1] to build because a typo in some
> > package declaration.  The error message is not very helpful,
> >
> >          srfi/srfi-1.scm:241:2: In procedure map:
> >          In procedure map: Wrong type argument: "https://www.qt.io/";
> >          building pages in '/tmp/gnu.org/software/guix'...
> ISTM this "wrong type argument" is an infuriatingly common
> and typically useless error message.
>
> Would it be possible to have a debugging hook where the message is output
> which if activated would show the call stack, so one could see where in
> the user code it happened?
>
> Activation could I imagine be by guile checking e.g.
> "GUILE_THROW_DEBUG_WRONG_ARGUMENT" on invocation, to turn on the hook
> in a way that would have zero performance effect if not activated.

Why a hook / environment variable in Guile? Backtraces are printed
by default, I do not see the benefit of disabling them by default and
adding an environment variable to enable them:

> antipode@antipode ~$ guile -c '(map 0 1)'
> Backtrace:
> In ice-9/boot-9.scm:
>   1752:10  6 (with-exception-handler _ _ #:unwind? _ # _)
> In unknown file:
>            5 (apply-smob/0 #<thunk 7fa30cc882e0>)
> In ice-9/boot-9.scm:
>     724:2  4 (call-with-prompt ("prompt") #<procedure 7fa30cc9acc0 …> …)
> In ice-9/eval.scm:
>     619:8  3 (_ #(#(#<directory (guile-user) 7fa30cc8dc80>)))
> In ice-9/command-line.scm:
>    185:19  2 (_ #<input: string 7fa30cc87850>)
> In unknown file:
>            1 (eval (map 0 1) #<directory (guile-user) 7fa30cc8dc80>)
> In ice-9/boot-9.scm:
>     218:9  0 (map 0 1)
>
> ice-9/boot-9.scm:218:9: In procedure map:
> In procedure map: Not a list: 1
Problem is already solved.

It appears that the website code catches exceptions and prints the error 
message,
but forgets to print the backtrace, but that seems to be a choice that 
the website
code made, not Guile. (Likely, an accidental choice, that can be improved.)

Greetings,
Maxime.

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