bug#23969: hard to understand error message

[ludo@gnu.org (Ludovic Courtès)]

Hi,

Vincent Legoll <vincent.legoll@gmail.com> skribis:

> I'm discovering guix, and started to try to package something.
>
> I made an error (add a string URL parameter to license x11-style):
>
> (license x11-style "file://LICENSE")
>
> But this is not working, because I've forgotten the scheme call syntax
> (missing parens)
>
> I'll fix my package definition with:
>
> (license (x11-style "file://LICENSE"))
>
> which seems to be working OK...
>
> But the error message I got was very unhelpful:
>
> something.scm:10:2: warning: source expression failed to match any pattern
>
> the line 10 is:
>   (package
>
> whereas the real error happened on line 32 (the license one)
>
> So what's wrong:
> - wrong line number
> - 'source expression' meaning is shady, as there is a "(source (origin
> ...))" element defined in the package, which is also not on line 10,
> but misleading anyways

Indeed.  This is fixed or at least improved in commit
babc2c80a7e1f1b5e72fd1685ef6604b93157a8e.  Now the message looks like:

--8<---------------cut here---------------start------------->8---
ice-9/psyntax.scm:1422:32: Syntax error:
gnu/packages/idutils.scm:42:4: package: invalid field specifier in form (synopsis "Identifier database utilities" foo)
--8<---------------cut here---------------end--------------->8---

Thanks,
Ludo’.