anchor.diff:  { lib, stdenv
   , fetchFromGitHub
  +, fetchpatch
   , nix-update-script
   , pantheon
   , pkg-config
  
positive.code: 
  stdenv.mkDerivation rec {
    pname = "wingpanel-indicator-nightlight";
    version = "2.0.4";
  
    src = fetchFromGitHub {
      owner = "elementary";
      repo = pname;
      rev = version;
      sha256 = "sha256-0f03XO74ezzS/Uy0mXT4raoazETL/SOVh58sAo9bEIA=";
    };
  
    passthru = {
      updateScript = nix-update-script {
  
negative.code:     wingpanel
    ];
  
    meta = with lib; {
      description = "Night Light Indicator for Wingpanel";
      homepage = "https://github.com/elementary/wingpanel-indicator-nightlight";
  