anchor.diff:    sourceRoot = "${appName}.app";
   
     src = fetchurl {
  -    url =  "ftp://ftp.osuosl.org/pub/musescore/releases/MuseScore-${concatStringsSep "." (take 3 versionComponents)}/MuseScore-${version}.dmg";
  -    sha256 = "19xkaxlkbrhvfip6n3iw6q7463ngr6y5gfisrpjqg2xl2igyl795";
  +    url =  "https://github.com/musescore/MuseScore/releases/download/v${concatStringsSep "." (take 3 versionComponents)}/MuseScore-${version}.dmg";
  +    sha256 = "sha256-lHckfhTTrDzaGwlbnZ5w0O1gMPbRmrmgATIGMY517l0=";
     };
   
     buildInputs = [ undmg ];
  
positive.code: { stdenv, lib, fetchurl, undmg }:
  
  let
    versionComponents = [ "2" "1" ];
    appName = "MuseScore ${builtins.head versionComponents}";
  in
  
  
negative.code:   meta = with lib; {
      description = "Music notation and composition software";
      homepage = "https://musescore.org/";
      license = licenses.gpl3Only;
      platforms = platforms.darwin;
      maintainers = [];
    };
  