[bug#43193] [PATCH] guix: Add --with-dependency-source option

[Ludovic Courtès]

Hi Jesse,

Jesse Gibbons <jgibbons2357@gmail.com> skribis:

>     The attached patch adds support for the --with-dependency-source
> common build option. It can be used to specify the sources of
> dependencies of specified packages. With this step, we can close
> #42155. This is also a step in closing #43061.

Excellent!

> Note that I suggested making a new
> --with-dependency-source=package=source build option in response to
> #42155 and nobody responded with an objection. So I am sending this
> patch with the assumption that there are no objections to this new
> build option, and that if a member of the community wants to
> completely replace the behavior of --with-source with the behavior of
> the new option, that person can do the work required to not break
> --with-source=source.

OK.  Like I wrote at <https://issues.guix.gnu.org/42155#3>, I wouldn’t
mind simply calling this new option ‘--with-source’.  What we’d lose by
doing so is the warning you get if you do
‘--with-source=does-not-exist=whatever’, saying the option had no
effect, but that’s about it.  The new ‘--with-source’ behavior
(recursive) would be consistent with the other options, which, to me, is
more important.

WDYT?

>>From 91a89277067fd454ad77edb3a09ed06382f3694c Mon Sep 17 00:00:00 2001
> From: Jesse Gibbons <jgibbons2357+guix@gmail.com>
> Date: Thu, 3 Sep 2020 17:45:08 -0600
> Subject: [PATCH v1 1/1] guix: Add --with-dependency-source option
>
> * guix/scripts/build.scm: (transform-package-inputs/source): new
>   function
> (evaluate-source-replacement-specs): new function
> (%transformations): add with-dependency-source option
> (%transformation-options): add with-dependency-source-option
> (show-transformation-options-help): document --with-dependency-source

[...]

> +(define (evaluate-source-replacement-specs specs proc)
> +  "Parse SPECS, a list of strings like \"guile=/path/to/source\", and return 
> a
> +list of package pairs, where (PROC PACKAGE URL) returns the replacement 
> package.
> +Raise an error if an element of SPECS uses invalid syntax, or if a package it
> +refers to could not be found."
> +  (map (lambda (spec)
> +         (match (string-tokenize spec %not-equal)
> +           ((spec url)
> +            (define (replace old)
> +              (proc old url))
> +            (cons spec replace))
> +           (x
> +            (leave (G_ "invalid replacement specification: ~s~%") spec))))
                                  ^
Add “source” here.  It’s always a good idea to not have the exact same
error message in several places.  :-)

Could you:

  1. adjust doc/guix.texi accordingly?  That is, if we rename this new
     option to ‘--with-source’, simply add a note stating that it’s
     recursive.

  2. add a test to tests/guix-build.sh?  There are already --with-source
     tests in other files.  You can mimic them, essentially to make sure
     the option has an effect.

  3. optionally add an entry as a separate commit to
     etc/news.scm.  I can do that for you if you want.

Thanks!

Ludo’.