nixos/gcr-ssh-agent: init

- `base16-builder` node package has been removed due to lack of upstream maintenance.

- `gnome-keyring` no longer ships with an SSH agent anymore because it has been deprecated upstream. You should use `gcr_4` instead, which provides the same features. More information on why this was done can be found on [the relevant GCR upstream PR](https://gitlab.gnome.org/GNOME/gcr/-/merge_requests/67).

## Other Notable Changes {#sec-nixpkgs-release-25.11-notable-changes}

<!-- To avoid merge conflicts, consider adding your item at an arbitrary place in the list instead. -->

- `amdgpu` kernel driver overdrive mode can now be enabled by setting [hardware.amdgpu.overdrive.enable](#opt-hardware.amdgpu.overdrive.enable) and customized through [hardware.amdgpu.overdrive.ppfeaturemask](#opt-hardware.amdgpu.overdrive.ppfeaturemask).

  This allows for fine-grained control over the GPU's performance and maybe required by overclocking softwares like Corectrl and Lact. These new options replace old options such as {option}`programs.corectrl.gpuOverclock.enable` and {option}`programs.tuxclocker.enableAMD`.

- [](#opt-services.gnome.gnome-keyring.enable) does not ship with an SSH agent anymore, as this is now handled by the `gcr_4` package instead of `gnome-keyring`. A new module has been added to support this, under [](#opt-services.gnome.gcr-ssh-agent.enable) (its default value has been set to [](#opt-services.gnome.gnome-keyring.enable) to ensure a smooth transition). See the [relevant upstream PR](https://gitlab.gnome.org/GNOME/gcr/-/merge_requests/67) for more details.

  ./services/desktops/geoclue2.nix

  ./services/desktops/gnome/at-spi2-core.nix

  ./services/desktops/gnome/evolution-data-server.nix

  ./services/desktops/gnome/gcr-ssh-agent.nix

  ./services/desktops/gnome/glib-networking.nix

  ./services/desktops/gnome/gnome-browser-connector.nix

  ./services/desktops/gnome/gnome-initial-setup.nix

{

  config,

  options,

  pkgs,

  lib,

  ...

}:

let

  cfg = config.services.gnome.gcr-ssh-agent;

  opts = options.services.gnome.gcr-ssh-agent;

  sshCfg = config.programs.ssh;

  sshOpts = options.programs.ssh;

in

{

  meta = {

    maintainers = lib.teams.gnome.members;

  };

  options = {

    services.gnome.gcr-ssh-agent = {

      enable = lib.mkOption {

        default = config.services.gnome.gnome-keyring.enable;

        defaultText = lib.literalExpression "config.services.gnome.gnome-keyring.enable";

        example = true;

        description = "Whether to enable GCR SSH agent.";

        type = lib.types.bool;

      };

      package = lib.mkPackageOption pkgs "GCR" {

        default = [ "gcr_4" ];

      };

    };

  };

  config = lib.mkIf cfg.enable {

    assertions = lib.singleton {

      assertion = !sshCfg.startAgent;

      message = ''

        `${sshOpts.startAgent}' (defined in ${lib.showFiles sshOpts.startAgent.files}) and `${opts.enable}' (defined in ${lib.showFiles opts.enable.files}) cannot both be enabled at the same time.

        These options conflict because only one SSH agent can be installed at a time.'';

    };

    systemd = {

      packages = [ cfg.package ];

      user.services.gcr-ssh-agent.wantedBy = [ "default.target" ];

      user.sockets.gcr-ssh-agent.wantedBy = [ "sockets.target" ];

    };

  };

}