nixos/gnome: Update core apps

https://blogs.gnome.org/mcatanzaro/2025/03/21/gnome-48-core-apps-update/

- Add Decibels 5d89ffdee4
  (It somewhat overlaps with GNOME Music but the latter remains for Music library.)
- Remove gnome-shell-extensions 490c573b1b
- Add Sysprof and D-Spy to developer tools.

nixos/doc/manual/release-notes/rl-2505.section.md

@@ -24,7 +24,13 @@
 
 - OpenSSH has been updated from 9.9p2 to 10.0p2, dropping support for DSA keys and adding a new `ssh-auth` binary to handle user authentication in a different address space from unauthenticated sessions. Additionally, we now enable a configure option by default that attempts to lock sshd into RAM to prevent it from being swapped out, which may improve performance if the system is under memory pressure. See the [full changelog](https://www.openwall.com/lists/oss-security/2025/04/09/1) for more details.
 
-- GNOME has been updated to version 48. Refer to the [GNOME release notes](https://release.gnome.org/48/) for more details.
+- GNOME has been updated to version 48.
+
+  - `decibels` music player is now installed by default. You can disable it using [](#opt-environment.gnome.excludePackages).
+  - `gnome-shell-extensions` extension collection (which included GNOME Classic extensions, Apps Menu, and User Themes, among others) are no longer installed by default. You can install them again with [](#opt-services.xserver.desktopManager.gnome.sessionPath).
+  - Option [](#opt-services.gnome.core-developer-tools.enable) now also installs `sysprof` and `d-spy`.
+
+  Refer to the [GNOME release notes](https://release.gnome.org/48/) for more details.
 
 - The `intel` video driver for X.org (from the xf86-video-intel package) which was previously removed because it was non-functional has been fixed and the driver has been re-introduced.
 

nixos/modules/services/x11/desktop-managers/gnome.nix

@@ -325,17 +325,9 @@ in
     })
 
     (lib.mkIf serviceCfg.core-shell.enable {
-      services.xserver.desktopManager.gnome.sessionPath =
-        let
-          mandatoryPackages = [
-            pkgs.gnome-shell
-          ];
-          optionalPackages = [
-            pkgs.gnome-shell-extensions
-          ];
-        in
-        mandatoryPackages
-        ++ utils.removePackagesByName optionalPackages config.environment.gnome.excludePackages;
+      services.xserver.desktopManager.gnome.sessionPath = [
+        pkgs.gnome-shell
+      ];
 
       services.colord.enable = mkDefault true;
       services.gnome.glib-networking.enable = true;
@@ -386,7 +378,7 @@ in
         source-sans
       ];
 
-      # Adapt from https://gitlab.gnome.org/GNOME/gnome-build-meta/blob/gnome-3-38/elements/core/meta-gnome-core-shell.bst
+      # Adapt from https://gitlab.gnome.org/GNOME/gnome-build-meta/blob/gnome-48/elements/core/meta-gnome-core-shell.bst
       environment.systemPackages =
         let
           mandatoryPackages = [
@@ -399,7 +391,6 @@ in
             pkgs.gnome-bluetooth
             pkgs.gnome-color-manager
             pkgs.gnome-control-center
-            pkgs.gnome-shell-extensions
             pkgs.gnome-tour # GNOME Shell detects the .desktop file on first log-in.
             pkgs.gnome-user-docs
             pkgs.glib # for gsettings program
@@ -413,11 +404,12 @@ in
         ++ utils.removePackagesByName optionalPackages config.environment.gnome.excludePackages;
     })
 
-    # Adapt from https://gitlab.gnome.org/GNOME/gnome-build-meta/-/blob/gnome-45/elements/core/meta-gnome-core-utilities.bst
+    # Adapt from https://gitlab.gnome.org/GNOME/gnome-build-meta/-/blob/gnome-48/elements/core/meta-gnome-core-apps.bst
     (lib.mkIf serviceCfg.core-utilities.enable {
       environment.systemPackages = utils.removePackagesByName (
         [
           pkgs.baobab
+          pkgs.decibels
           pkgs.epiphany
           pkgs.gnome-text-editor
           pkgs.gnome-calculator
@@ -499,17 +491,19 @@ in
       ] config.environment.gnome.excludePackages;
     })
 
-    # Adapt from https://gitlab.gnome.org/GNOME/gnome-build-meta/-/blob/3.38.0/elements/core/meta-gnome-core-developer-tools.bst
+    # Adapt from https://gitlab.gnome.org/GNOME/gnome-build-meta/-/blob/gnome-48/elements/core/meta-gnome-core-developer-tools.bst
     (lib.mkIf serviceCfg.core-developer-tools.enable {
       environment.systemPackages = utils.removePackagesByName [
         pkgs.dconf-editor
         pkgs.devhelp
+        pkgs.d-spy
         pkgs.gnome-builder
         # boxes would make sense in this option, however
         # it doesn't function well enough to be included
         # in default configurations.
         # https://github.com/NixOS/nixpkgs/issues/60908
         # pkgs.gnome-boxes
+        pkgs.sysprof
       ] config.environment.gnome.excludePackages;
 
       services.sysprof.enable = notExcluded pkgs.sysprof;