anchor.diff:    meta = with lib; {
       homepage = "https://docs.xfce.org/panel-plugins/xfce4-mailwatch-plugin";
       description = "Mail watcher plugin for Xfce panel";
  -    license = licenses.gpl2;
  +    license = licenses.gpl2Only;
       platforms = platforms.linux;
       maintainers = [ ];
     };
  
positive.code: 
  stdenv.mkDerivation rec {
    pname  = "xfce4-mailwatch-plugin";
    version = "1.2.0";
  
    src = fetchurl {
      url = "mirror://xfce/src/${category}/${pname}/${lib.versions.majorMinor version}/${pname}-${version}.tar.bz2";
      sha256 = "1bfw3smwivr9mzdyq768biqrl4aq94zqi3xjzq6kqnd8561cqjk2";
    };
  
    nativeBuildInputs = [
  
negative.code: { lib, stdenv, fetchurl, pkg-config, intltool, xfce4-panel, libxfce4ui,
    exo, gnutls, libgcrypt, xfce }:
  
  let
    category = "panel-plugins";
  