[bug#69940] [PATCH 0/2] Making a 'guix' package with specific channels

[bug#69940] [PATCH 0/2] Making a 'guix' package with specific channels

[Ludovic Courtès]

From: Ludovic Courtès <ludovic.courtes@inria.fr>

Hello Guix!

This patch series aims to allow users to create an operating system
that runs a specific Guix for ‘guix-service-type’, and in particular
for /run/current-system/profile/bin/guix: it could be the ‘guix’
channel pinned to a specific revision, or it could be ‘guix’ together
with additional channels.  Here’s the example added in the new
section of the manual:

     (use-modules (guix channels))

     (define my-channels
       ;; Channels that should be available to
       ;; /run/current-system/profile/bin/guix.
       (append
        (list (channel
               (name 'guix-science)
               (url "https://github.com/guix-science/guix-science")
               (branch "master")))
        %default-channels))

     (operating-system
       ;; ...
       (services
         ;; Change the package used by 'guix-service-type'.
         (modify-services %base-services
           (guix-service-type
            config => (guix-configuration
                       (inherit config)
                       (channels my-channels)
                       (guix (guix-for-channels my-channels)))))))

The resulting operating system will have both the ‘guix’ and the
‘guix-science’ channels visible by default.  The ‘channels’ field of
‘guix-configuration’ above ensures that /etc/guix/channels.scm specifies
the same set of channels

Thoughts?

Thanks,
Ludo’.

Ludovic Courtès (2):
  build-system/channel: Add support for additional channels.
  gnu: guix: Define ‘guix-for-channels’ and document its use.

 doc/guix.texi                       | 67 ++++++++++++++++++++++++++++-
 gnu/packages/package-management.scm | 14 +++++-
 guix/build-system/channel.scm       |  7 ++-
 3 files changed, 83 insertions(+), 5 deletions(-)


base-commit: 40f53e8fb5b867e3a1e8fa798328423718282aac
-- 
2.41.0

[bug#69940] [PATCH 1/2] build-system/channel: Add support for additional channels.

[Ludovic Courtès]

Until now, ‘channel-build-system’ would assume a single channel, the
‘guix’ channel.  This change lets users specify additional channels
using the #:channels parameter.

* guix/build-system/channel.scm (build-channels): Add #:channels and
honor it.
(channel-build-system): In ‘lower’, add #:channels and honor it.
* doc/guix.texi (Build Systems): Document it.

Change-Id: I36c1d19cbeee02a4d1144de089b78df0390774a0
---
 doc/guix.texi                 | 5 ++++-
 guix/build-system/channel.scm | 7 +++++--
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/doc/guix.texi b/doc/guix.texi
index eda4084e7f..07dc6e24a8 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -10451,7 +10451,10 @@ Build Systems
 name, in which case an additional @code{#:commit} argument must be
 supplied to specify the commit being built (a hexadecimal string).
 
-The resulting package is a Guix instance of the given channel, similar
+Optionally, a @code{#:channels} argument specifying additional channels
+can be provided.
+
+The resulting package is a Guix instance of the given channel(s), similar
 to how @command{guix time-machine} would build it.
 @end defvar
 
diff --git a/guix/build-system/channel.scm b/guix/build-system/channel.scm
index 6ad377f930..0607dcf4d7 100644
--- a/guix/build-system/channel.scm
+++ b/guix/build-system/channel.scm
@@ -1,5 +1,5 @@
 ;;; GNU Guix --- Functional package management for GNU
-;;; Copyright © 2019-2022 Ludovic Courtès <ludo@gnu.org>
+;;; Copyright © 2019-2022, 2024 Ludovic Courtès <ludo@gnu.org>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -37,6 +37,7 @@ (define latest-channel-instances*
 
 (define* (build-channels name inputs
                          #:key source system commit
+                         (channels '())
                          (authenticate? #t)
                          #:allow-other-keys)
   (mlet* %store-monad ((instances
@@ -44,7 +45,7 @@ (define* (build-channels name inputs
                                (return (list source)))
                               ((channel? source)
                                (latest-channel-instances*
-                                (list source)
+                                (cons source channels)
                                 #:authenticate? authenticate?))
                               ((string? source)
                                ;; If SOURCE is a store file name, as is the
@@ -64,12 +65,14 @@ (define* (build-channels name inputs
 (define channel-build-system
   ;; Build system used to "convert" a channel instance to a package.
   (let ((lower (lambda* (name #:key system source commit (authenticate? #t)
+                              (channels '())
                               #:allow-other-keys)
                  (bag
                    (name name)
                    (system system)
                    (build build-channels)
                    (arguments `(#:source ,source
+                                #:channels ,channels
                                 #:authenticate? ,authenticate?
                                 #:commit ,commit))))))
     (build-system (name 'channel)
-- 
2.41.0

[bug#69940] [PATCH 2/2] gnu: guix: Define ‘guix-for-channels’ and document its use.

[Ludovic Courtès]

From: Ludovic Courtès <ludovic.courtes@inria.fr>

* gnu/packages/package-management.scm (guix-for-channels): New
procedure.
* doc/guix.texi (Customizing the System-Wide Guix): New section.
(Base Services): Add cross-reference.

Change-Id: Ied51c3bf9bf08dfc629bb3f0a152eb20b869a636
---
 doc/guix.texi                       | 62 ++++++++++++++++++++++++++++-
 gnu/packages/package-management.scm | 14 ++++++-
 2 files changed, 74 insertions(+), 2 deletions(-)

diff --git a/doc/guix.texi b/doc/guix.texi
index 07dc6e24a8..a2d5ef3ffd 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -5514,6 +5514,7 @@ Channels
 * Specifying Additional Channels::  Extending the package collection.
 * Using a Custom Guix Channel::  Using a customized Guix.
 * Replicating Guix::            Running the @emph{exact same} Guix.
+* Customizing the System-Wide Guix:: Default channels on Guix System.
 * Channel Authentication::      How Guix verifies what it fetches.
 * Channels with Substitutes::   Using channels with available substitutes.
 * Creating a Channel::          How to write your custom channel.
@@ -5671,6 +5672,64 @@ Replicating Guix
 will---some sort of ``meta reproducibility'' capabilities, if you will.
 @xref{Inferiors}, for another way to take advantage of these super powers.
 
+@node Customizing the System-Wide Guix
+@section Customizing the System-Wide Guix
+
+@cindex system-wide Guix, customization
+@cindex channels, for the default Guix
+If you're running Guix System or building system images with it, maybe
+you will want to customize the system-wide @command{guix} it
+provides---specifically, @file{/run/current-system/profile/bin/guix}.
+For example, you might want to provide additional channels or to pin its
+revision.
+
+This can be done using the @code{guix-for-channels} procedure, which
+returns a package for the given channels, and using it as part of your
+operating system configuration, as in this example:
+
+@lisp
+(use-modules (guix channels))
+
+(define my-channels
+  ;; Channels that should be available to
+  ;; /run/current-system/profile/bin/guix.
+  (append
+   (list (channel
+          (name 'guix-science)
+          (url "https://github.com/guix-science/guix-science")
+          (branch "master")))
+   %default-channels))
+
+(operating-system
+  ;; @dots{}
+  (services
+    ;; Change the package used by 'guix-service-type'.
+    (modify-services %base-services
+      (guix-service-type
+       config => (guix-configuration
+                  (inherit config)
+                  (channels my-channels)
+                  (guix (guix-for-channels my-channels)))))))
+@end lisp
+
+The resulting operating system will have both the @code{guix} and the
+@code{guix-science} channels visible by default.  The @code{channels}
+field of @code{guix-configuration} above further ensures that
+@file{/etc/guix/channels.scm}, which is used by @command{guix pull},
+specifies the same set of channels (@pxref{guix-configuration-channels,
+@code{channels} field of @code{guix-configuration}}).
+
+The @code{(gnu packages package-management)} module exports the
+@code{guix-for-channels} procedure, described below.
+
+@deffn {Procedure} guix-for-channels @var{channels}
+Return a package corresponding to @var{channels}.
+
+The result is a ``regular'' package, which can be used in
+@code{guix-configuration} as shown above or in any other place that
+expects a package.
+@end deffn
+
 @node Channel Authentication
 @section Channel Authentication
 
@@ -19734,7 +19793,8 @@ Base Services
 
 @table @asis
 @item @code{guix} (default: @var{guix})
-The Guix package to use.
+The Guix package to use.  @xref{Customizing the System-Wide Guix} to
+learn how to provide a package with a pre-configured set of channels.
 
 @item @code{build-group} (default: @code{"guixbuild"})
 Name of the group for build user accounts.
diff --git a/gnu/packages/package-management.scm b/gnu/packages/package-management.scm
index e9dd7427d3..c59f8b2bba 100644
--- a/gnu/packages/package-management.scm
+++ b/gnu/packages/package-management.scm
@@ -1,5 +1,5 @@
 ;;; GNU Guix --- Functional package management for GNU
-;;; Copyright © 2013-2023 Ludovic Courtès <ludo@gnu.org>
+;;; Copyright © 2013-2024 Ludovic Courtès <ludo@gnu.org>
 ;;; Copyright © 2015, 2017, 2020, 2021, 2022, 2023 Ricardo Wurmus <rekado@elephly.net>
 ;;; Copyright © 2017 Muriithi Frederick Muriuki <fredmanglis@gmail.com>
 ;;; Copyright © 2017, 2018 Oleg Pykhalov <go.wigust@gmail.com>
@@ -649,6 +649,18 @@ (define-public guix-minimal
       (modify-inputs (package-propagated-inputs guix)
         (delete "guile-ssh"))))))
 
+(define-public (guix-for-channels channels)
+  "Return a package corresponding to CHANNELS."
+  (package
+    (inherit guix)
+    (source (find guix-channel? channels))
+    (build-system channel-build-system)
+    (arguments
+     `(#:channels ,(remove guix-channel? channels)))
+    (inputs '())
+    (native-inputs '())
+    (propagated-inputs '())))
+
 (define-public current-guix-package
   ;; This parameter allows callers to override the package that 'current-guix'
   ;; returns.  This is useful when 'current-guix' cannot compute it by itself,
-- 
2.41.0

bug#69940: [PATCH 0/2] Making a 'guix' package with specific channels

[Ludovic Courtès]

Hello,

Ludovic Courtès <ludo@gnu.org> skribis:

>   build-system/channel: Add support for additional channels.
>   gnu: guix: Define ‘guix-for-channels’ and document its use.

Pushed as be14d41d9be3ef91d11ab24780855682c432cac9.

Ludo’.