On 28 Nov 2014 22:52, "Ludovic Courtès" <ludo@gnu.org> wrote:
>
> Deck Pickard <deck.r.pickard@gmail.com> skribis:
>
> > From 3693753aefc27b5a68a2b762feeebc41320e79ef Mon Sep 17 00:00:00 2001
> > From: nebuli <nebu@kipple>
> > 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?
>

Perhaps for one-off 15 minutes worth of compiles it's a OK, but not for
hours of work. And you are creating more confusion by having different
defaults from guix-daemon. Lastly, some unsuspecting newb   may still
stumble into N^2 trap with '-M <my number of shiny cores>'...  ouch, 36
threads competing for silicon on a 6 core box...

> > From fa8738ff2cf48886c9ef8fbacfa806f547f3c3c8 Mon Sep 17 00:00:00 2001
> > From: nebuli <nebu@kipple>
> > 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?
>

DONE,
Drp
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