[bug#70839] [PATCH 0/3] Minor changes to `channels' field and related doc.

[bug#70839] [PATCH 0/3] Minor changes to `channels' field and related doc.

[Tomas Volf]

As discussed on mailing list[0], this series contains few minor changes to
documentation, changing the default value to #f and creating new procedure for
actually filling the `channels' field based on the channels.scm file.

0: https://lists.gnu.org/archive/html/guix-devel/2024-04/msg00049.html

Tomas Volf (3):
  doc: Warn about extra-special-file usage in /etc.
  channels: Add `read-channels-file' procedure.
  services: guix: Default `channels' field to #f.

 doc/guix.texi         |  8 ++++++--
 gnu/services/base.scm |  2 +-
 guix/channels.scm     | 14 +++++++++++++-
 guix/scripts/pull.scm | 12 +++---------
 4 files changed, 23 insertions(+), 13 deletions(-)

--
2.41.0

[bug#70839] [PATCH 1/3] doc: Warn about extra-special-file usage in /etc.

[Tomas Volf]

* doc/guix.texi (Base Services)[extra-special-file]: Add warning regarding
files in /etc.

Change-Id: Ic45465c8712d61caeed42d7912777368e8763a1a
---
 doc/guix.texi | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/doc/guix.texi b/doc/guix.texi
index f20208f94f..568878ad24 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -123,7 +123,7 @@
 Copyright @copyright{} 2023 Thomas Ieong@*
 Copyright @copyright{} 2023 Saku Laesvuori@*
 Copyright @copyright{} 2023 Graham James Addis@*
-Copyright @copyright{} 2023 Tomas Volf@*
+Copyright @copyright{} 2023, 2024 Tomas Volf@*
 Copyright @copyright{} 2024 Herman Rimm@*
 Copyright @copyright{} 2024 Matthew Trzcinski@*
 Copyright @copyright{} 2024 Richard Sent@*
@@ -18984,6 +18984,10 @@ Base Services
 (extra-special-file "/usr/bin/env"
                     (file-append coreutils "/bin/env"))
 @end lisp
+
+This procedure is meant for @code{/bin/sh}, @code{/usr/bin/env} and
+similar targets.  In particular, use for targets under @code{/etc} might
+not work as expected if the target is managed by Guix in other ways.
 @end deffn
 
 @defvar host-name-service-type
-- 
2.41.0

[bug#70839] [PATCH 2/3] channels: Add `read-channels-file' procedure.

[Tomas Volf]

This commit moves non-exported local procedure from (guix pull) in order to
provide a single, canonical way to read a file produced by `guix describe
--format=channels'.

* guix/channels.scm (read-channels-file): New procedure.
(define-module): Export it.
* guix/scripts/pull.scm (channel-list): Use it.

Change-Id: I147fdf3cb177114f4607209de2299f46761b64be
---
 guix/channels.scm     | 14 +++++++++++++-
 guix/scripts/pull.scm | 12 +++---------
 2 files changed, 16 insertions(+), 10 deletions(-)

diff --git a/guix/channels.scm b/guix/channels.scm
index 51024dcad4..38d5c8c325 100644
--- a/guix/channels.scm
+++ b/guix/channels.scm
@@ -37,6 +37,7 @@ (define-module (guix channels)
   #:autoload   (guix git-authenticate) (authenticate-repository)
   #:autoload   (guix openpgp) (openpgp-public-key-fingerprint
                                openpgp-format-fingerprint)
+  #:autoload   (guix ui) (load* make-user-module)
   #:use-module (guix base16)
   #:use-module (guix records)
   #:use-module (guix gexp)
@@ -111,7 +112,9 @@ (define-module (guix channels)
             channel-news-entry-title
             channel-news-entry-body
 
-            channel-news-for-commit))
+            channel-news-for-commit
+
+            read-channels-file))
 
 ;;; Commentary:
 ;;;
@@ -1086,6 +1089,15 @@ (define* (channel->code channel #:key (include-introduction? #t))
                                  intro))))))
             '()))))
 
+(define (read-channels-file file)
+  "Return channel list read from FILE.
+
+The file shall have format produced by `guix describe --format=channels'."
+  (let ((result (load* file (make-user-module '((guix channels))))))
+    (if (and (list? result) (every channel? result))
+        result
+        (leave (G_ "'~a' did not return a list of channels~%") file))))
+
 \f
 ;;;
 ;;; News.
diff --git a/guix/scripts/pull.scm b/guix/scripts/pull.scm
index 58d3cd7e83..7240b2f25e 100644
--- a/guix/scripts/pull.scm
+++ b/guix/scripts/pull.scm
@@ -750,21 +750,15 @@ (define (channel-list opts)
   (define global-file
     (string-append %sysconfdir "/guix/channels.scm"))
 
-  (define (load-channels file)
-    (let ((result (load* file (make-user-module '((guix channels))))))
-      (if (and (list? result) (every channel? result))
-          result
-          (leave (G_ "'~a' did not return a list of channels~%") file))))
-
   (define channels
     (cond (file
-           (load-channels file))
+           (read-channels-file file))
           ((and (not ignore-channel-files?)
                 (file-exists? default-file))
-           (load-channels default-file))
+           (read-channels-file default-file))
           ((and (not ignore-channel-files?)
                 (file-exists? global-file))
-           (load-channels global-file))
+           (read-channels-file global-file))
           (else
            %default-channels)))
 
-- 
2.41.0

[bug#70839] [PATCH 3/3] services: guix: Default `channels' field to #f.

[Tomas Volf]

In the absence of the /etc/guix/channels.scm file, %default-channels is used
anyway.  If user manually (or by extra-special-file) created the file, we
should respect it.  This commit therefore changes the default to #f, hopefully
having zero impact on people not actively using the `channels' field.

* gnu/services/base.scm (<guix-configuration>)[channels]: Set default to #f.

Change-Id: I516c1735a037a153fabbebfc337051aaf0be2155
---
 doc/guix.texi         | 2 +-
 gnu/services/base.scm | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/doc/guix.texi b/doc/guix.texi
index 568878ad24..9f422f8212 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -19591,7 +19591,7 @@ Base Services
 not need it and where the extra boot time is a problem.
 
 @anchor{guix-configuration-channels}
-@item @code{channels} (default: @code{%default-channels})
+@item @code{channels} (default: @code{#f})
 List of channels to be specified in @file{/etc/guix/channels.scm}, which
 is what @command{guix pull} uses by default (@pxref{Invoking guix
 pull}).
diff --git a/gnu/services/base.scm b/gnu/services/base.scm
index 85160bd3ab..c5f28fd611 100644
--- a/gnu/services/base.scm
+++ b/gnu/services/base.scm
@@ -1830,7 +1830,7 @@ (define-record-type* <guix-configuration>
   (generate-substitute-key? guix-configuration-generate-substitute-key?
                             (default #t))         ;Boolean
   (channels         guix-configuration-channels ;file-like
-                    (default %default-channels))
+                    (default #f))
   (chroot-directories guix-configuration-chroot-directories ;list of file-like/strings
                       (default '()))
   (max-silent-time  guix-configuration-max-silent-time ;integer
-- 
2.41.0