anchor.diff:  { config, pkgs, lib, ... }:
   let
  -  inherit (lib) mkOption types mkIf;
  +  inherit (lib) mapAttrs mkIf mkOption optional optionals types;
   
     cfg = config.services.kmscon;
   
  
positive.code:         description = "Whether to use 3D hardware acceleration to render the console.";
          type = types.bool;
          default = false;
        };
  
        extraConfig = mkOption {
  
negative.code: 
      systemd.services.systemd-vconsole-setup.enable = false;
  
      services.kmscon.extraConfig =
        let
          render = optionals cfg.hwRender [ "drm" "hwaccel" ];
          fonts = optional (cfg.fonts != null) "font-name=${lib.concatMapStringsSep ", " (f: f.name) cfg.fonts}";
        in lib.concatStringsSep "\n" (render ++ fonts);
  
      hardware.opengl.enable = mkIf cfg.hwRender true;
  
      fonts = mkIf (cfg.fonts != null) {
        fontconfig.enable = true;
        fonts = map (f: f.package) cfg.fonts;
      };
    };
  }
  