anchor.diff:      cp -r ../demos $out/share/furnace/
     '';
   
  -  passthru.updateScript = nix-update-script {
  -    attrPath = pname;
  +  passthru = {
  +    updateScript = gitUpdater {
  +      inherit pname version;
  +      rev-prefix = "v";
  +    };
  +    tests.version = testVersion {
  +      package = furnace;
  +      # The command always exits with code 1
  +      command = "(furnace --version || [ $? -eq 1 ])";
  +    };
     };
   
     meta = with lib; {
  
positive.code: { stdenv
  , lib
  , nix-update-script
  , fetchFromGitHub
  , fetchpatch
  , cmake
  , pkg-config
  , makeWrapper
  
negative.code: 
  stdenv.mkDerivation rec {
    pname = "furnace";
    version = "0.5.8";
  
    src = fetchFromGitHub {
      owner = "tildearrow";
      repo = "furnace";
      rev = "v${version}";
      fetchSubmodules = true;
      sha256 = "103ymd3wa1sfsr6qg15vpcs53j350i7zidv3azlf7cynk6k28xim";
    };
  
    postPatch = ''
      # rtmidi is not used yet
  