fractional scaling: rm support for X11

hosts/yodaTux/configuration.nix

@@ -29,8 +29,7 @@
       ../../modules/gnome-base.nix
       ../../modules/gnome-config.nix
       ../../modules/gnome-extensions.nix
-      # TODO currently broken
+      ../../modules/gnome-fractional-scaling.nix
-      #../../modules/gnome-fractional-scaling.nix
       ../../modules/fwupd-gnome.nix
       ../../modules/gnome-wallpaper.nix
 

modules/gnome-fractional-scaling.nix

@@ -1,10 +1,5 @@
 { config, pkgs, lib, ... }:
-let
-  version = "45.5";
-in
 {
-  # TODO: This module is broken for 46.2
-
   # https://wiki.archlinux.org/title/HiDPI#Wayland
   # Results in blurry font in non-Wayland applications :/
 
@@ -14,70 +9,23 @@ in
   #   "scale-monitor-framebuffer": This allows GNOME to scale each monitor’s framebuffer independently, which is necessary for per-monitor scaling.
   #   "x11-randr-fractional-scaling": This allows fractional scaling, which gives you finer control over the scaling factor.
 
-  # TODO open issue: Fractional scaling can't be enabled with multiple monitors.
+  # TODO: Open issue. Fractional scaling can't be enabled with multiple monitors.
+  # TODO: X11 or Wayland or both?
   #   https://gitlab.gnome.org/GNOME/gnome-control-center/-/issues/2076
   #   https://gitlab.gnome.org/GNOME/gnome-control-center/-/issues/2365
   #   -> https://bugs.launchpad.net/ubuntu/+source/gnome-control-center/+bug/2008355
 
+  assertions = [{
+    assertion = config.services.xserver.displayManager.gdm.wayland;
+    message = "Fractional scaling is only supported for Wayland. There is a patch for X11, but we no longer apply it in an overlay. See e.g. https://aur.archlinux.org/packages/mutter-x11-scaling";
+  }];
+
   programs.dconf.enable = true;
 
-  # Overlays.
-  # https://nixos.wiki/wiki/Overlays#In_NixOS
-  # https://discourse.nixos.org/t/use-specific-pkg-version-in-overlay/32741/3
-
-  # If on X11, then use patched version of mutter.
-  nixpkgs.overlays = lib.mkIf (! config.services.xserver.displayManager.gdm.wayland) [
-    (
-      # Patched version of mutter 44.2.
-      # Outdated example: https://nixos.wiki/wiki/Overlays#Overriding_a_package_inside_a_scope
-      #
-      # On the AUR, they apply only one patch, not three.
-      # And they pick the patch that corresponds to the mutter version.
-      # https://aur.archlinux.org/packages/mutter-x11-scaling
-      #
-      # New patch URL:
-      # -> https://salsa.debian.org/gnome-team/mutter/-/blob/ubuntu/master/debian/patches/ubuntu/x11-Add-support-for-fractional-scaling-using-Randr.patch
-      # For release 44.2:
-      # -> https://salsa.debian.org/gnome-team/mutter/-/tags?sort=updated_desc&search=ubuntu%2F
-      # -> https://salsa.debian.org/gnome-team/mutter/-/tags/ubuntu%2F44.2-3ubuntu1
-      # -> https://salsa.debian.org/gnome-team/mutter/-/raw/ubuntu/44.2-3ubuntu1/debian/patches/ubuntu/x11-Add-support-for-fractional-scaling-using-Randr.patch
-      # For release 45.3:
-      # -> https://salsa.debian.org/gnome-team/mutter/-/tags?sort=updated_desc&search=ubuntu%2F
-      # -> https://salsa.debian.org/gnome-team/mutter/-/tags/ubuntu%2F45.3-1ubuntu1
-      # -> https://salsa.debian.org/gnome-team/mutter/-/raw/ubuntu/45.3-1ubuntu1/debian/patches/ubuntu/x11-Add-support-for-fractional-scaling-using-Randr.patch
-
-      # Elements of nixpkgs must be taken from final and prev.
-      final: prev: {
-        # Elements of pkgs.gnome must be taken from gfinal and gprev.
-        gnome = prev.gnome.overrideScope' (gfinal: gprev: {
-          mutter = gprev.mutter.overrideAttrs (oldAttrs:
-            if oldAttrs.version == version then
-              {
-                patches = (oldAttrs.patches or []) ++ [
-                  (prev.fetchpatch {
-                    url = "https://salsa.debian.org/gnome-team/mutter/-/raw/ubuntu/${version}-1ubuntu1/debian/patches/ubuntu/x11-Add-support-for-fractional-scaling-using-Randr.patch";
-                    # Determining the hash: https://github.com/NixOS/nixpkgs/issues/191128#issuecomment-1246030431
-                    hash = "sha256-snEgCuTsTEo0wQ5XsjEM53K2j7l4ZQ3t9FT3+Yfoti0=";
-                  })
-                ];
-              }
-            else throw "Mutter version mismatch. Please update patch to ${oldAttrs.version}"
-          );
-        });
-      }
-    )
-  ];
-
   home-manager.users.yoda = { osConfig, config, pkgs, ... }: {
     dconf.settings = {
       "org/gnome/mutter" = {
-        experimental-features = (
+        experimental-features = ["scale-monitor-framebuffer" "xwayland-native-scaling"];
-          if (osConfig.services.xserver.displayManager.gdm.wayland)
-          # Wayland
-          then ["scale-monitor-framebuffer"]
-          # X11
-          else ["scale-monitor-framebuffer" "x11-randr-fractional-scaling"]
-        );
       };
     };
   };