[bug#68716] [PATCH gnome-team v3 5/5] services: gnome: Use a blocklist for udev configurations.

[Vivien Kraus via Guix-patches via <guix-patches@gnu.org>]

The gnome-udev-configuration-files now lists every udev rule and hardware
file, and remove files based on a user-supplied list of regular expressions.

* gnu/services/desktop.scm (gnome-desktop-configuration): Add the
udev-blocklist field.
(gnome-udev-configuration-files): Change behavior.

Change-Id: I6df4b896652581c42a35ea3ba1e4849ad72d12ef
---
 gnu/services/desktop.scm | 46 +++++++++++++++++++++++++++-------------
 1 file changed, 31 insertions(+), 15 deletions(-)

diff --git a/gnu/services/desktop.scm b/gnu/services/desktop.scm
index 263ae61698..f04e99ba9a 100644
--- a/gnu/services/desktop.scm
+++ b/gnu/services/desktop.scm
@@ -87,6 +87,7 @@ (define-module (gnu services desktop)
   #:use-module (guix ui)
   #:use-module (guix utils)
   #:use-module (guix gexp)
+  #:use-module (guix modules)
   #:use-module (srfi srfi-1)
   #:use-module (srfi srfi-26)
   #:use-module (srfi srfi-35)
@@ -156,6 +157,7 @@ (define-module (gnu services desktop)
             gnome-desktop-configuration-shell
             gnome-desktop-configuration-utilities
             gnome-desktop-configuration-extra-packages
+            gnome-desktop-configuration-udev-blocklist
             gnome-desktop-service
             gnome-desktop-service-type
 
@@ -1494,7 +1496,12 @@ (define-configuration/no-serialization gnome-desktop-configuration
    "A list of GNOME-adjacent packages to also include.  This field is intended
 for users to add their own packages to their GNOME experience.  Note, that it
 already includes some packages that are considered essential by some (most?)
-GNOME users."))
+GNOME users.")
+  (udev-blocklist
+   (list-of-strings '())
+   "A list of regular expressions denoting udev rules or hardware file names
+provided by any package, that should not be installed.  By default, every udev
+rule and hardware file specified by all packages are installed."))
 
 (define (gnome-package gnome name)
   "Return the package NAME among the GNOME package inputs.  NAME can be a
@@ -1509,20 +1516,29 @@ (define (gnome-packages gnome names)
 (define (gnome-udev-configuration-files config)
   "Return the list of GNOME dependencies that provide udev rules and hardware
 files."
-  (let* ((gnome (gnome-desktop-configuration-gnome config))
-         (shell (gnome-desktop-configuration-shell config)))
-    (or (any (match-lambda
-               ((and pkg (= package-name "gnome-settings-daemon"))
-                (list pkg))
-               (_ #f))
-             shell)
-        (and (maybe-value-set? gnome)
-             (gnome-packages gnome '("gnome-settings-daemon")))
-        (raise
-         (condition
-          (&error-location
-           (location (gnome-desktop-configuration-source-location config)))
-          (&message (message (G_ "Missing gnome-settings-daemon"))))))))
+  (list
+   (computed-file
+    "gnome-udev-configurations"
+    (with-imported-modules
+        (source-module-closure '((guix build utils)
+                                 (guix build union)))
+      #~(begin
+          (use-modules (guix build utils)
+                       (guix build union))
+          ;; If rules.d or hwdb.d is not a proper directory but a symlink,
+          ;; then it will not be possible to delete individual files in this
+          ;; directory.
+          (union-build #$output
+                       (search-path-as-list
+                        (list "lib/udev" "libexec/udev")
+                        (list #$@(gnome-profile config)))
+                       #:create-all-directories? #t)
+          (for-each
+           (lambda (pattern)
+             (for-each
+              delete-file-recursively
+              (find-files #$output pattern)))
+           (list #$@(gnome-desktop-configuration-udev-blocklist config))))))))
 
 (define (gnome-polkit-settings config)
   "Return the list of GNOME dependencies that provide polkit actions and
-- 
2.41.0