GNOME

GNOME (/(ɡ)noʊm/) is a desktop environment known for its focus on being simple, intuitive, and easy to use. It is made by The GNOME Project and is composed entirely of free and open-source software. Its Mutter compositor supports both Wayland and X server, and the GNOME Shell user interface is customizable by extensions.

This article is an extension of the documentation in the NixOS manual.

GNOME is available as a module and can be enabled with services.xserver.desktopManager.

Installation

To use GNOME, add this to your configuration.nix:

/etc/nixos/configuration.nix

{
  services.xserver.enable = true;
  services.xserver.displayManager.gdm.enable = true;
  services.xserver.desktopManager.gnome.enable = true;
}

Excluding GNOME Applications

To exclude certain applications that are installed by default with GNOME edit configuration.nix as follows:

/etc/nixos/configuration.nix

{
  environment.gnome.excludePackages = (with pkgs; [
    # for packages that are pkgs.*
    gnome-tour
    gnome-connections
  ]) ++ (with pkgs.gnome; [
    # for packages that are pkgs.gnome.*
    epiphany # web browser
    geary # email reader
    evince # document viewer
  ]);
}

Configuration

Managing extensions

GNOME extensions are managed and configured by the program "Extensions" that comes with GNOME. Some of them can be installed with Nix, however they aren't enabled by default. To enable them the "Extensions" program can be used.

/etc/nixos/configuration.nix

{
  environment.systemPackages = with pkgs.gnomeExtensions; [
    blur-my-shell
    pop-shell
    # ...
  ];
}

Installed extensions can be enabled and configured in Extension app that comes preinstalled with GNOME. If you want to do that declaratively in your configuration, you can use Home Manager dconf module by adding following lines.

~/.config/home-manager/home.nix

{
  dconf = {
    enable = true;
    settings = {
      "org/gnome/shell" = {
        disable-user-extensions = false; # enables user extensions
        enabled-extensions = [
          # Put UUIDs of extensions that you want to enable here.
          # If the extension you want to enable is packaged in nixpkgs,
          # you can easily get its UUID by accessing its extensionUuid
          # field (look at the following example).
          pkgs.gnomeExtensions.gsconnect.extensionUuid
          
          # Alternatively, you can manually pass UUID as a string.  
          "blur-my-shell@aunetx"
          # ...
        ];
      };

      # Configure individual extensions
      "org/gnome/shell/extensions/blur-my-shell" = {
        brightness = 0.75;
        noise-amount = 0;
      };
    };
  };
}

dconf settings

Most of the GNOME settings are stored in dconf database. Settings are stored as keys placed in folders.

To learn about settings that can be configured with dconf either look into dconf-editor program (provided by gnome.dconf-editor package) or type dconf watch / in the terminal and change settings from the GUI and see which options are responsible for that component/element.

These settings can be changed by NixOS via programs.dconf module or by Home Manager via dconf module. To so in Home Manager, you need to change dconf.settings attribute set. This attribute set contains absolute folder paths (without leading slash) as attributes' names which value is another attribute set with keys (settings).

For example, to change the value of clock-show-weekday key that is located in /org/gnome/desktop/interface, you need to the following:

~/.config/home-manager/home.nix

{
  dconf.settings = {
    enable = true;

    # You need quotes to escape '/'
    "org/gnome/desktop/interface" = {
      clock-show-weekday = true;
    };
  };
}

Same can be achieved by using system configuration.

/etc/nixos/configuration.nix

{
  programs.dconf = {
    enable = true;
    profiles.user.databases = [
      {
        lockAll = true; # prevents overriding
        settings = {
          "org/gnome/desktop/interface" = {
            clock-show-weekday = true;
          };
        };
      }
    ];
  };
}

Note: Since dconf have more data types than Nix language (for example, tuples), in some cases you'll need to convert Nix value to a GVariant value. You can achieve that by using function defined in lib.gvariant, they're documented here.

Dark mode

Change default color theme for all GTK4 applications to dark using Home Manager.

~/.config/home-manager/home.nix

{
  dconf = {
    enable = true;
    settings."org/gnome/desktop/interface".color-scheme = "prefer-dark";
  };
}

Tips and tricks

To run GNOME programs outside of GNOME

GNOME platform-based applications are largely self-contained, but they still depend, for one reason or another, on some global configuration. The gnome.nix module sets all the necessary options for you but if you are running customized set-up, you might need to replicate that yourself.

For instance, if you see the following error:

dconf-WARNING **: failed to commit changes to dconf: GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name ca.desrt.dconf was not provided by any .service files

you should enable dconf module:

{
  programs.dconf.enable = true;
}

Many applications rely heavily on having an icon theme available, GNOME’s Adwaita is a good choice but most recent icon themes should work as well.

{
  environment.systemPackages = with pkgs; [ gnome.adwaita-icon-theme ];
}

Systray Icons

To get systray icons, install the related GNOME shell extension

{
  environment.systemPackages = [ pkgs.gnomeExtensions.appindicator ];
}

And ensure gnome-settings-daemon udev rules are enabled:

{
  services.udev.packages = [ pkgs.gnome.gnome-settings-daemon ];
}

To run old applications

Some old applications use GConf service to store configuration. This has been deprecated for many years but some applications were abandoned before they managed to upgrade to a newer dconf system. If you are running such application and getting an error like:

GLib.GException: Failed to contact configuration server; the most common cause is a missing or misconfigured D-Bus session bus daemon. See http://projects.gnome.org/gconf/ for information

you need to add gnome2.GConf to the list of dbus packages in your configuration.nix:

{
  services.dbus.packages = with pkgs; [ gnome2.GConf ];
}

After applying the update restart your desktop session to refresh the user-specific dbus session.

Dynamic triple buffering

Warning: Dynamic triple buffering is a still developing feature that is not merged into GNOME's mutter. Some bugs and unexpected behavior can occur. Use at your own risk!

Big merge request against Mutter improves the performance of the window manager by a lot (and is already used by Ubuntu). Not merged into nixpkgs due to philosophy of nixpkgs, but users are free to add this overlay to get it too.

If you wish to try this patch for yourself, add the following to your NixOS configuration:

/etc/nixos/configuration.nix

{
  nixpkgs.overlays = [
    # GNOME 46: triple-buffering-v4-46
    (final: prev: {
      gnome = prev.gnome.overrideScope (gnomeFinal: gnomePrev: {
        mutter = gnomePrev.mutter.overrideAttrs (old: {
          src = pkgs.fetchFromGitLab  {
            domain = "gitlab.gnome.org";
            owner = "vanvugt";
            repo = "mutter";
            rev = "triple-buffering-v4-46";
            hash = "sha256-fkPjB/5DPBX06t7yj0Rb3UEuu5b9mu3aS+jhH18+lpI=";
          };
        });
      });
    })
  ];
}

You might need to disable aliases to make it work:

  nixpkgs.config.allowAliases = false;

NOTE - the "allowAliases" set to false has been known to break stylix (if you use it).

Profiling (with sysprof)

Install sysprof as a system package (it won't work properly if installed against users). Then enable the associated service with

  services.sysprof.enable = true;

Automatic screen rotation

  hardware.sensor.iio.enable = true;

Troubleshoots

Change user's profile picture

Currently there is no way to change the user's profile picture using Gnome Control Center (see this issue) and currently there is no plan to support it officially in NixOS. However, you can modify it by copying the profile picture that you want to the path /home/$USER/.face as a workaround, i.e.

$ mv /path/to/image.jpg ~/.face

Change Profile Photo for Login and Lockscreen - Declarative

This is admittedly a hack way of doing it, however does work.

Considerations:

• image must be a PNG
• permissions matter
• this is absolutely a workaround
• assumes you are already using a .face file
• you will need to update the paths and username as applicable to your system (CAPITALIZED in the code)
• you cannot change the photo using Gnome Control Center

You can place this in your configuration.nix:

system.activationScripts.script.text = ''
    mkdir -p /var/lib/AccountsService/{icons,users}
    cp /home/YOUR-USER-NAME/PATH-TO/.face /var/lib/AccountsService/icons/YOUR-USER-NAME
    echo -e "[User]\nIcon=/var/lib/AccountsService/icons/YOUR-USER-NAME\n" > /var/lib/AccountsService/users/YOUR-USER-NAME

    chown root:root /var/lib/AccountsService/users/YOUR-USER-NAME
    chmod 0600 /var/lib/AccountsService/users/YOUR-USER-NAME

    chown root:root /var/lib/AccountsService/icons/YOUR-USER-NAME
    chmod 0444 /var/lib/AccountsService/icons/YOUR-USER-NAME
'';

Automatic login

If you have enabled auto login (with GNOME) with something like

$ grep autoLogin /etc/nixos/configuration.nix

services.xserver.displayManager.autoLogin.enable = true;
services.xserver.displayManager.autoLogin.user = "account";

than add the following (as a workaround for a current (2023) problem)

# nano /etc/nixos/configuration.nix

{
  systemd.services."getty@tty1".enable = false;
  systemd.services."autovt@tty1".enable = false;
}

See also

• GNOME/Calendar