[bug#50620] [PATCH 1/2] guix: packages: Document 'computed-origin-method'.

[Liliana Marie Prikler <liliana.prikler@gmail.com>]

Hi,

Am Donnerstag, den 16.09.2021, 13:47 +0200 schrieb zimoun:
> The 'computed-origin-method' had been introduced as a workaround
> limitations in the 'snippet' mechanism.  The procedure is duplicated
> which makes hard to automatically detects packages using it.
> 
> * guix/packages.scm (computed-origin-method): Move procedure from...
> * gnu/packages/gnuzilla.scm: ...here and...
> * gnu/packages/gnuzilla.scm: ...there.
> ---
>  gnu/packages/gnuzilla.scm | 14 ++------------
>  gnu/packages/linux.scm    | 14 ++------------
>  guix/packages.scm         | 23 ++++++++++++++++++++++-
>  3 files changed, 26 insertions(+), 25 deletions(-)
> 
> diff --git a/gnu/packages/gnuzilla.scm b/gnu/packages/gnuzilla.scm
> index 431b487fd0..9f6e1f24e1 100644
> --- a/gnu/packages/gnuzilla.scm
> +++ b/gnu/packages/gnuzilla.scm
> @@ -682,18 +682,8 @@ in C/C++.")
>     ("1j6l66v1xw27z8w78mpsnmqgv8m277mf4r0hgqcrb4zx7xc2vqyy"
> "527e5e090608" "zh-CN")
>     ("1frwx35klpyz3sdwrkz7945ivb2dwaawhhyfnz4092h9hn7rc4ky"
> "6cd366ad2947" "zh-TW")))
>  
> -(define* (computed-origin-method gexp-promise hash-algo hash
> -                                 #:optional (name "source")
> -                                 #:key (system (%current-system))
> -                                 (guile (default-guile)))
> -  "Return a derivation that executes the G-expression that results
> -from forcing GEXP-PROMISE."
> -  (mlet %store-monad ((guile (package->derivation guile system)))
> -    (gexp->derivation (or name "computed-origin")
> -                      (force gexp-promise)
> -                      #:graft? #f       ;nothing to graft
> -                      #:system system
> -                      #:guile-for-build guile)))
> +;; XXXX: Workaround 'snippet' limitations.
> +(define computed-origin-method (@@ (guix packages) computed-origin-
> method))
>  
>  (define %icecat-version "78.14.0-guix0-preview1")
>  (define %icecat-build-id "20210907000000") ;must be of the form
> YYYYMMDDhhmmss
> diff --git a/gnu/packages/linux.scm b/gnu/packages/linux.scm
> index 285eb132f4..eb792be9a3 100644
> --- a/gnu/packages/linux.scm
> +++ b/gnu/packages/linux.scm
> @@ -216,18 +216,8 @@ defconfig.  Return the appropriate make target
> if applicable, otherwise return
>            (file-name (string-append "linux-libre-deblob-check-"
> version "-" gnu-revision))
>            (sha256 deblob-check-hash))))
>  
> -(define* (computed-origin-method gexp-promise hash-algo hash
> -                                 #:optional (name "source")
> -                                 #:key (system (%current-system))
> -                                 (guile (default-guile)))
> -  "Return a derivation that executes the G-expression that results
> -from forcing GEXP-PROMISE."
> -  (mlet %store-monad ((guile (package->derivation guile system)))
> -    (gexp->derivation (or name "computed-origin")
> -                      (force gexp-promise)
> -                      #:graft? #f       ;nothing to graft
> -                      #:system system
> -                      #:guile-for-build guile)))
> +;; XXXX: Workaround 'snippet' limitations
> +(define computed-origin-method (@@ (guix packages) computed-origin-
> method))
>  
>  (define (make-linux-libre-source version
>                                   upstream-source
> diff --git a/guix/packages.scm b/guix/packages.scm
> index ad7937b4fb..8c3a0b0b7b 100644
> --- a/guix/packages.scm
> +++ b/guix/packages.scm
> @@ -1,6 +1,6 @@
>  ;;; GNU Guix --- Functional package management for GNU
>  ;;; Copyright © 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019,
> 2020, 2021 Ludovic Courtès <ludo@gnu.org>
> -;;; Copyright © 2014, 2015, 2017, 2018 Mark H Weaver <mhw@netris.org
> >
> +;;; Copyright © 2014, 2015, 2017, 2018, 2019 Mark H Weaver <
> mhw@netris.org>
>  ;;; Copyright © 2015 Eric Bavier <bavier@member.fsf.org>
>  ;;; Copyright © 2016 Alex Kost <alezost@gmail.com>
>  ;;; Copyright © 2017, 2019, 2020 Efraim Flashner <
> efraim@flashner.co.il>
> @@ -344,6 +344,27 @@ name of its URI."
>           ;; git, svn, cvs, etc. reference
>           #f))))
>  
> +;; Work around limitations in the 'snippet' mechanism.  It is not
> possible for
> +;; a 'snippet' to produce a tarball with a different base name than
> the
> +;; original downloaded source.  Moreover, cherry picking dozens of
> upsteam
> +;; patches and applying them suddenly is often impractical;
> especially when a
> +;; comprehensive code reformatting is done upstream.  Mainly
> designed for
> +;; Linux and IceCat packages.
> +;; XXXX: do not make part of public API (export) such radical
> capability
> +;; before a detailed review process.
> +(define* (computed-origin-method gexp-promise hash-algo hash
> +                                 #:optional (name "source")
> +                                 #:key (system (%current-system))
> +                                 (guile (default-guile)))
> +  "Return a derivation that executes the G-expression that results
> +from forcing GEXP-PROMISE."
> +  (mlet %store-monad ((guile (package->derivation guile system)))
> +    (gexp->derivation (or name "computed-origin")
> +                      (force gexp-promise)
> +                      #:graft? #f       ;nothing to graft
> +                      #:system system
> +                      #:guile-for-build guile)))
> +
>  
>  (define %supported-systems
>    ;; This is the list of system types that are supported.  By
> default, we
I think that rather than putting this into (guix packages) itself, we
might want to put it into its own file like (guix computed-origins) and
choose a method name that is actually a verb, similar to git-fetch or
svn-fetch.  Perhaps simply call it compute-origin?

If done this way, there'd be the benefit that modules with packages
using this thing would have to explicitly request the presence of the
symbol through their use-modules clauses.  WDYT?