anchor.diff:  
   stdenv.mkDerivation rec {
     pname = "arc-theme";
  -  version = "20210127";
  +  version = "20210412";
   
     src = fetchFromGitHub {
       owner = "jnsh";
       repo = pname;
       rev = version;
  -    sha256 = "sha256-P7YZTD5bAWNWepL7qsZZAMf8ujzNbHOj/SLx8Fw3bi4=";
  +    sha256 = "sha256-BNJirtBtdWsIzQfsJsZzg1zFbJEzZPq1j2qZ+1QjRH8=";
     };
   
     nativeBuildInputs = [
  -    autoreconfHook
  +    meson
  +    ninja
       pkg-config
       sassc
       optipng
       inkscape
       gtk3
  +    glib # for glib-compile-resources
     ];
   
     propagatedUserEnvPkgs = [
  
positive.code:     gtk-engine-murrine
    ];
  
    enableParallelBuilding = true;
  
    preBuild = ''
      # Shut up inkscape's warnings about creating profile directory
      export HOME="$NIX_BUILD_ROOT"
    '';
  
    configureFlags = [
      "--with-cinnamon=${cinnamon.cinnamon-common.version}"
      "--with-gnome-shell=${gnome.gnome-shell.version}"
      "--disable-unity"
    ];
  
    postInstall = ''
      install -Dm644 -t $out/share/doc/${pname} AUTHORS *.md
    '';
  
    meta = with lib; {
      description = "Flat theme with transparent elements for GTK 3, GTK 2 and Gnome Shell";
  
negative.code: { lib, stdenv
  , fetchFromGitHub
  , sassc
  , meson
  , ninja
  , pkg-config
  , gtk3
  , glib
  , gnome
  , gtk-engine-murrine
  , optipng
  