anchor.diff:          {
             assertion = cfg.style != null && any (name: name == cfg.style.name) styles;
             message = "`qt5.style.name` is not one of [ ${toString styles} ].";
  +        }
  +        {
  +          assertion = cfg.font == null && cfg.iconTheme == null;
  +          message = "`qt5.font` and `qt5.iconTheme` are only supported by kde platform.";
           }
         ];
         environment.variables.QT_QPA_PLATFORMTHEME = "gtk2";
  
positive.code: 
      environment.variables = attrByPath [ cfg.platformTheme "environment" "variables" ] {} platforms;
  
      environment.systemPackages = attrByPath [ cfg.platformTheme "environment" "systemPackages" ] [] platforms
        ++ optionalPackage cfg.style;
  
    };
  
  
negative.code:         </varlistentry>
        '';
  
        assertions = [
          {
            assertion = cfg.font == null && cfg.iconTheme == null;
            message = "`qt5.font` and `qt5.iconTheme` are only supported by kde platform.";
          }
        ];
        environment.variables.QT_QPA_PLATFORMTHEME = "qgnomeplatform";
        # TODO: make this optional once https://github.com/NixOS/nixpkgs/issues/54150 is fixed
        # qgnomeplatform reads theme and other settings from dconf db
        environment.variables.QT_STYLE_OVERRIDE = cfg.style.name;
        environment.variables.XDG_DATA_DIRS = [ "${pkgs.gsettings-desktop-schemas}/share/gsettings-schemas/${pkgs.gsettings-desktop-schemas.name}" ];
        environment.systemPackages = [ pkgs.qgnomeplatform ];
      };
      gtk3 = {
        description = ''
          <varlistentry>
            <term><literal>gtk3</literal></term>
            <listitem><para>Use GNOME theme with
              <link xlink:href="https://code.qt.io/cgit/qt/qtbase.git/tree/src/plugins/platformthemes/gtk3">gtk3</link>
            </para></listitem>
          </varlistentry>
        '';
  
        assertions = [
          {
            assertion = cfg.style != null;
            message = "`qt5.platformTheme` gtk3 requires `qt5.style` to be set.";
          }
          {
            assertion = cfg.font == null && cfg.iconTheme == null;
            message = "`qt5.font` and `qt5.iconTheme` are only supported by kde platform.";
          }
        ];
        environment.variables.QT_QPA_PLATFORMTHEME = "gtk3";
        environment.variables.QT_STYLE_OVERRIDE = cfg.style.name;
      };
      kde = {
        description = ''
          <varlistentry>
            <term><literal>kde</literal></term>
            <listitem><para>Use Qt theme with
              <link xlink:href="https://code.qt.io/cgit/qt/qtbase.git/tree/src/platformsupport/themes/genericunix">qkdetheme</link>
            </para></listitem>
          </varlistentry>
        '';
  
        environment.variables.XDG_CURRENT_DESKTOP = mkForce "KDE";
        environment.variables.KDE_SESSION_VERSION = "5";
        environment.etc."xdg/kdeglobals".text =
          toQtIni {
            General = general;
            Icons = icons;
          };
      };
    };
  in
  