Hi Ludo,

I've had to re-read some parts of the manual and the code of (guix
store) a bit to completely understand this one, so thank you for the
practical lesson too.  :-)

To be sure that I understood it: the main difference is that now
package-with-source _stages_ (wink) the source download up to the gexp
compilation, isn't it?  If that's the case, this LGTM and my quick
tests.

Happy hacking,
Miguel

Ludovic Courtès <ludo@gnu.org> writes:

> * guix/scripts/build.scm (<downloaded-file>): New record type.
> (download-to-store*): New variable.
> (compile-downloaded-file): New procedure.
> (package-with-source): Remove 'store' parameter.  Use 'downloaded-file'
> instead of 'download-to-store'.
> (transform-package-source): Adjust accordingly.
> ---
>  guix/scripts/build.scm | 26 ++++++++++++++++++++++----
>  1 file changed, 22 insertions(+), 4 deletions(-)
>
> diff --git a/guix/scripts/build.scm b/guix/scripts/build.scm
> index f4a8af035b..831ac8f798 100644
> --- a/guix/scripts/build.scm
> +++ b/guix/scripts/build.scm
> @@ -45,6 +45,7 @@
>    #:use-module (ice-9 match)
>    #:use-module (ice-9 vlist)
>    #:use-module (srfi srfi-1)
> +  #:use-module (srfi srfi-9)
>    #:use-module (srfi srfi-11)
>    #:use-module (srfi srfi-26)
>    #:use-module (srfi srfi-34)
> @@ -172,7 +173,25 @@ extensions."
>          (else
>           file-name)))
>  
> -(define* (package-with-source store p uri #:optional version)
> +
> +;; Files to be downloaded.
> +(define-record-type <downloaded-file>
> +  (downloaded-file uri recursive?)
> +  downloaded-file?
> +  (uri        downloaded-file-uri)
> +  (recursive? downloaded-file-recursive?))
> +
> +(define download-to-store*
> +  (store-lift download-to-store))
> +
> +(define-gexp-compiler (compile-downloaded-file (file <downloaded-file>)
> +                                               system target)
> +  "Download FILE and return the result as a store item."
> +  (match file
> +    (($ <downloaded-file> uri recursive?)
> +     (download-to-store* uri #:recursive? recursive?))))
> +
> +(define* (package-with-source p uri #:optional version)
>    "Return a package based on P but with its source taken from URI.  Extract
>  the new package's version number from URI."
>    (let ((base (tarball-base-name (basename uri))))
> @@ -183,8 +202,7 @@ the new package's version number from URI."
>                              (package-version p)))
>  
>                 ;; Use #:recursive? #t to allow for directories.
> -               (source (download-to-store store uri
> -                                          #:recursive? #t))
> +               (source (downloaded-file uri #t))
>  
>                 ;; Override the replacement, otherwise '--with-source' would
>                 ;; have no effect.
> @@ -226,7 +244,7 @@ matching URIs given in SOURCES."
>          ((? package? p)
>           (match (assoc-ref sources (package-name p))
>             ((version source)
> -            (package-with-source store p source version))
> +            (package-with-source p source version))
>             (#f
>              p)))
>          (_