Re: [PATCH 2/6] build-system/emacs: Use "emacs" from native-inputs if specified.

[ludo@gnu.org (Ludovic Courtès)]

Federico Beffa <beffa@ieee.org> skribis:

> Alex Kost <alezost@gmail.com> writes:
>
>> * guix/build-system/emacs.scm (lower): Do not add "emacs" to
>>   build-inputs if it is already specified in the native-inputs.
>> @@ -73,8 +75,16 @@
>>
>>                          ;; Keep the standard inputs of 'gnu-build-system'.
>>                          ,@(standard-packages)))
>> -         (build-inputs `(("emacs" ,emacs)
>> -                         ,@native-inputs))
>> +         ;; Add emacs to build-inputs only if native-inputs do not contain
>> +         ;; emacs already.  This allows us to use non-default emacs for
>> +         ;; building.
>> +         (build-inputs (if (find (match-lambda
>> +                                   (("emacs" _ ...) #t)
>> +                                   (_ #f))
>> +                                 native-inputs)
>> +                           native-inputs
>> +                           `(("emacs" ,emacs)
>> +                             ,@native-inputs)))
>
> Note that for the interpreter we normally use a keyword, here #:emacs
> (in a similar way as, say, for the python-build-system there is
> #:python).  Your code overwrites its effect in a non-transparent way.

Seconded, I prefer #:emacs, which is consistent with cmake-build-system,
python-build-system, etc.

Ludo’.