Re: Source location behavior differs in REPL and script?

[Jean Abou Samra <jean@abou-samra.fr>]

Le 24/07/2022 à 14:26, Jean Abou Samra a écrit :
> Hi,
>
> For context, I'm trying to fix issues with source locations
> from embedded Scheme code in LilyPond. Essentially, with
> Guile 2.2, errors are displayed without any source location
> info because the evaluator doesn't provide them. The compiler
> does, so I'm investigating whether we can use it.
>
> So far, I've been experimenting in the REPL, and tearing my
> hair because I couldn't get locations to work. My test started
> to become inconvenient to modify in the REPL at some point,
> so I switched to putting that code in a .scm file. To my
> great surprise, that made locations suddenly work.
>
> Example:
>
> (use-modules (system base compile))
>
> (define code-str
>   "
> (begin
>   (debug-disable 'backtrace)
>   (define (func1 x)
>     (func2 x)
>     (func2 x)
>     (func2 x))
>
>   (define (func2 x)
>     (display (func3 x))
>     (write (func3 x))
>     (map write (func3 x)))
>
>   (define (func3 x)
>     (error \"Oops\"))
>
>   (func1 #f))
>   ")
>
> (define code-synt
>   (call-with-input-string
>    code-str
>    (lambda (port)
>      (set-port-filename! port "fake.scm")
>      (read-syntax port))))
>
> (compile code-synt)
>
>
> When I paste this in the REPL, the given error is
>
> ice-9/boot-9.scm:1685:16: In procedure raise-exception:
> Oops
>
>
> When I put it in tests.scm and run "guile3.0 tests.scm",
> the error is
>
> fake.scm:15:4: In procedure func1:
> Oops
>
>
> When I put it in a LilyPond file, the result is
>
> Oops
>
> (without any location info at all).
>
> Does anyone have a clue about what causes these differences?
> Is it expected? Should I report it as a bug? Also, is there a
> workaround?


Well, 10 minutes later, I have my answer. Both the REPL and LilyPond
use catch to be robust against errors, printing the backtraces but
not exiting themselves. I need to investigate if there is a way
to get the location when catching an exception.

Sorry for the noise,
Jean