anchor.diff:    meta = with lib; {
       description = "Music notation and composition software";
       homepage = "https://musescore.org/";
  -    license = licenses.gpl2;
  +    license = licenses.gpl3Only;
       platforms = platforms.darwin;
       maintainers = [];
     };
  
positive.code:   sourceRoot = "${appName}.app";
  
    src = fetchurl {
      url =  "ftp://ftp.osuosl.org/pub/musescore/releases/MuseScore-${concatStringsSep "." (take 3 versionComponents)}/MuseScore-${version}.dmg";
      sha256 = "19xkaxlkbrhvfip6n3iw6q7463ngr6y5gfisrpjqg2xl2igyl795";
    };
  
    buildInputs = [ undmg ];
  
negative.code: { stdenv, lib, fetchurl, undmg }:
  
  let
    versionComponents = [ "3" "6" "2" "548020600" ];
    appName = "MuseScore ${builtins.head versionComponents}";
  in
  
  