Subject: Re: bug#53165: "guix import opam coq-of-ocaml" unexpected error

From: zimoun <[email-masked]>
Date: Tue, 11 Jan 2022 11:51:51 +0100

Hi,

On Mon, 10 Jan 2022 at 21:36, raingloom <[email-masked]> wrote:

> My guess is that the package is missing a description? I vaguely recall
> running into this or a similar error when trying to import Infer, but
> I'm not sure how I fixed it.
> Based on the backtrace, just modifying beautify-description? to act as
> the identity function when the input isn't a string should be enough.

Thanks.  If no one beats me, I will give a look.  But for now it is low
in my list. :-)

> This is why Scheme should have a Maybe type instead of this mess of
> overloading boolean false. :)
> Or at least Guile should have an optional type checker like MyPy.

Hm, I do not think Maybe would change something if the «package is
missing a description».  At best, Maybe would be another way to catch
the errors instead of raising the Backtrace, no?

And I do not think that a type checker like MyPy would raises something
here if the issue comes from the missing upstream description, no?

Something like QuickCheck seems required and would raise the bug,
eventually.  Oh wait, guile-quickcheck is around [1] and used by
Disarchive; therefore already an indirect dependency of guix. :-)

That’s said, nothing prevents Guile to have a Maybe monad.  But I think
this way of programming is not popular among Schemers. :-) And I agree
that a type checker would prevent many issues.  Even, I remember talking
this topic back on December 2018 around this event:
<https://lists.gnu.org/archive/html/guix-devel/2018-12/msg00049.html>. ;-)

Cheers,
simon

1: <https://ngyro.com/software/guile-quickcheck.html>