Subject: Re: [bug#34982] [PATCH] guile-build-system: Support building in parallel.
From: Christopher Baines <[email-masked]>
To: Ludovic Courtès <[email-masked]>
Cc: [email-masked]
Date: Fri, 19 Apr 2019 08:43:39 +0100
List-Id: <debbugs-submit.debbugs.gnu.org>

Ludovic Courtès <[email-masked]> writes:

> Christopher Baines <[email-masked]> skribis:
>
>> * guix/build/guile-build-system.scm (build): Use invoke-each, instead of
>> for-each, to use multiple cores if available.
>> (invoke-each, report-build-process): New procedures.
>
> [...]
>
>> +  (define (fork-and-run-command command)
>> +    (match (primitive-fork)
>> +      (0
>> +       (apply execlp command))
>> +      (pid
>> +       #t)))
>
> To be on the safe side, you should probably wrap the ‘execlp’ call like
> this:
>
>   (dynamic-wind
>     (const #t)
>     (lambda ()
>       (apply execlp command))
>     (lambda ()
>       (primitive-exit 127)))
>
> This ensures that the child process exits immediately if something goes
> wrong (e.g., ‘execlp’ raises an exception because the executable could
> not be found.)
>
> Otherwise LGTM, thank you!

Great, I've added in dynamic-wind, made some minor tweaks to the output,
and pushed this as 3fdb9a375f1cee7dd302349a9527437df20b3f61.

Thanks for taking a look :)

Chris