On Mon, 11 Sep 2017 14:12:34 +0200
ludo@gnu.org (Ludovic Courtès) wrote:

> Hello!
> 
> Christopher Baines <mail@cbaines.net> skribis:
> 
> > So I'm having some trouble using the Guile json module in a gexp.
> > I've added (with-imported-modules '((json)) ...), and the
> > module-import-compiled builder crashes.
> >
> > Backtrace:
> >            4 (primitive-load
> > "/gnu/store/35zv0m9wwd2nz3agyywv09d3k5v?") In srfi/srfi-1.scm:
> >     640:9  3 (for-each #<procedure c10700 at
> > ice-9/eval.scm:333:13 ?> ?) In ice-9/eval.scm:
> >    245:16  2 (_ #(#(#<directory (guix build utils) 83f6e0> "/gn?")
> > #)) In ice-9/boot-9.scm:
> >   1519:24  1 (_ "./json.scm")
> > In unknown file:
> >            0 (stat "./json.scm" #<undefined>)
> >
> > ERROR: In procedure stat:
> > ERROR: In procedure stat: No such file or directory: "./json.scm"  
> 
> This would have the effect of importing the (json) module of the host
> environment into the build environment, which is not desirable for a
> couple of reasons:
> 
>   1. It would require having Guile-JSON installed in the host
>      environment, and the right version of it.
> 
>   2. It would hinder reproducibility since different users may have
>      different Guile-JSON variants installed on the host side.
> 
> To overcome this, you have to do like (guix scripts package) does:
> 
>   #~(begin
>       (add-to-load-path #$(file-append guile-json
>                                        "/share/guile/site/"
>                                        (effective-version)))
>       …)
> 
> It would be nice to simplify this somehow, though.

Awesome, thanks Ludo.

Your explaination makes lots of sense, and the approach you suggested
worked perfectly :)