Re: [PATCH] Core sanity and taking build options from environment.

[Ludovic Courtès]

Deck Pickard <address@hidden> skribis:

> From 3693753aefc27b5a68a2b762feeebc41320e79ef Mon Sep 17 00:00:00 2001
> From: nebuli <address@hidden>
> Date: Wed, 26 Nov 2014 19:51:37 +0100
> Subject: [PATCH 1/2] guix: Default to daemon's default --cores setting of 1.

I think most of the time one would prefer to use all the available cores
when building.  WDYT?

> From fa8738ff2cf48886c9ef8fbacfa806f547f3c3c8 Mon Sep 17 00:00:00 2001
> From: nebuli <address@hidden>
> Date: Thu, 27 Nov 2014 23:36:29 +0100
> Subject: [PATCH 2/2] guix: scripts: Add handling of options from GUIX_BUILD
>  environmental variable.

[...]

> --- a/guix/scripts/build.scm
> +++ b/guix/scripts/build.scm
> @@ -401,7 +401,13 @@ arguments with packages that use the specified source."
>  (define (guix-build . args)
>    (define (parse-options)
>      ;; Return the alist of option values.
> -    (args-fold* args %options
> +    (args-fold* (append args
> +                        (args-from-env "GUIX_BUILD"
> +                                       (lambda (var opts)
> +                                         (format (current-error-port)
> +                                                 (_ "guix build: ~a: ~a~%")
> +                                                 var opts))))
> +                %options

This sounds like a good idea.

Some suggestions that come to mind:

  • What about $GUIX_BUILD_OPTIONS?  (grep uses $GREP_OPTIONS, for
    reference.)

  • What about factorizing the above ‘args-from-env’ call like this:

    (define (environment-build-options)
      "Return additional build options passed as environment variables."
      (args-from-env "GUIX_BUILD_OPTIONS"))

    This procedure would go in (guix ui).

  • I would leave out the second argument to ‘args-from-env’.  I don’t
    think it would be convenient to have that extra line printed every
    time.

> +(define (args-from-env var . rest)
> +  "Retrieve value of environment variable denoted by string VAR in the form
> +of a list of strings ('char-set:graphic' tokens) suitable for consumption by
> +the fold-arg family of functions.  If VAR is defined, call car of a non-null

s/fold-arg family of functions/'args-fold'/

> +REST on the VAR and result, otherwise return an empty list."
> +  (let ((env-opts (getenv variable)))
> +    (if env-opts
> +        (let ((opts (string-tokenize env-opts char-set:graphic)))
> +          (and (not (null? rest))
> +               (apply (car rest)
> +                      (list variable opts)))
> +          opts)
> +        '())))

Please write it like this:

  (define (arguments-from-environment-variable variable)
    (let ((env (getenv variable)))
      ...))

Could you also update guix.texi, near the end of “Invoking guix build”?

WDYT?  Could you send an updated patch?

Thank you,
Ludo’.