Ludovic Courtès writes:

> Christopher Allan Webber <cwebber@dustycloud.org> skribis:
>
>>           (let* ((out (assoc-ref %outputs "out"))
>> -                (module-dir (string-append out "/share/guile/site/2.0"))
>> +                (module-dir (string-append out "/share/guile/site/"
>> +                                           ,(if guile-2.2?
>> +                                                "2.2" "2.0")))
>>                  (source (assoc-ref %build-inputs "source"))
>
> Another approach, which is more future-proof but also more verbose, is
> to evaluate (effective-version) for the Guile that’s being used, on the
> “build side” (thus, no need to do the unquote thing above).
>
> The ‘guile-minikanren’ package does exactly that:
>
>          (let* ((out (assoc-ref %outputs "out"))
>                 (guile (assoc-ref %build-inputs "guile"))
>                 (effective (read-line
>                             (open-pipe* OPEN_READ
>                                         (string-append guile "/bin/guile")
>                                         "-c" "(display (effective-version))")))
>                 (module-dir (string-append out "/share/guile/site/"
>                                            effective)) …)
>             …)
>
> We should probably factorize this somewhere (a new (guix build guile)
> module?), but for now that’s what we have.
>
> How does that sound?

It looks much better!  I've updated my patch to use this method.

Re: the new module, I agree it's a good idea.  We had some talks at
FOSDEM about maybe supporting more declarative guild'y type
configuration again, and maybe that's the right approach, I don't really
know.  It feels like "what should we do about easy to package guile
packages that don't necessarily use autotools" is still a conversation
to be had.  Not sure if that's a prerequisite for the module.

Anyway, okay to push?  I'd love to have the buggy package not be buggy
in master. :)