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

[Ludovic Courtès]

Hi,

Jesse Gibbons <jgibbons2357@gmail.com> skribis:

>> 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.
> I included this in the attached patch.
>>    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.
>>
> Do you still think the tests should be updated and this change should
> be announced in the news file? I'm willing to do these.

Yes, please.  There’s should be a test that checks that --with-source
works for non-leaf packages.  A new entry would also be nice.

> From 2786da1e7011c59f08fc150dfa284f35bc0ed093 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 1/1] guix: Make --with-source option recursive
>
> * guix/scripts/build.scm: (transform-package-inputs/source): new
>   function
> (evaluate-source-replacement-specs): new function
> (%transformations): change with-source to use
> evaluate-source-replacement-specs
>
> *doc/guix.texi (Package Transformation Options): Document it.

Nitpick: There are spacing and capitalization issues.  Please see ‘git
log’ for examples.

> +++ b/doc/guix.texi
> @@ -9129,7 +9129,8 @@ without having to type in the definitions of package 
> variants
>  @itemx --with-source=@var{package}=@var{source}
>  @itemx --with-source=@var{package}@@@var{version}=@var{source}
>  Use @var{source} as the source of @var{package}, and @var{version} as
> -its version number.
> +its version number.  This replacement is applied recursively on all
> +dependencies only if PACKAGE is specified.

s/PACKAGE/@var{package}/

However, the semantics are a bit “weird”.  I would just do the recursive
replacement thing unconditionally.  WDYT?

> +(define (transform-package-inputs/source replacement-specs)
> +  "Return a procedure that, when passed a package, replaces its direct
> +dependencies according to REPLACEMENT-SPECS.  REPLACEMENT-SPECS is a list of
> +strings like \"guile=/path/to/source\" or
> +\"guile=https://www.example.com/guile-source.tar.gz\"; meaning that, any
> +dependency on a package called \"guile\" must be replaced with a dependency 
> on a
> +\"guile\" built with the source at the specified location."
> +  (match (string-tokenize (car replacement-specs) %not-equal)
> +    ((spec url)

s/url/file/ since it’s a file name.

> +     (lambda (store obj)
> +       (let* ((replacements (evaluate-source-replacement-specs 
> replacement-specs
> +                                                               (lambda (old 
> url)
> +                                                                 
> (package-with-source store old url))))
> +              (rewrite (package-input-rewriting/spec replacements))
> +              (rewrite* (lambda (obj)
> +                          (rewrite obj))))
> +         (if (package? obj)
> +             (rewrite* obj)
> +             obj))))
> +    ((url)
> +     (transform-package-source replacement-specs))))

So maybe drop the second clause for non-recursive replacement, and drop
‘transform-package-source’ as well.

Thanks!

Ludo’.