anchor.diff:  
     doCheck = true;
     checkPhase = ''
  +    runHook preCheck
       pushd regtest
   
       mkdir -p "$TMP"/{log,regtest}
  
positive.code: { lib, stdenv, fetchurl, pkg-config, gettext, which
  , glib, gtk2
  , enableSoftening ? true
  }:
  
  stdenv.mkDerivation rec {
    pname = "dvdisaster";
    version = "0.79.5";
  
    src = fetchurl {
      url = "http://dvdisaster.net/downloads/${pname}-${version}.tar.bz2";
      sha256 = "0f8gjnia2fxcbmhl8b3qkr5b7idl8m855dw7xw2fnmbqwvcm6k4w";
    };
  
    nativeBuildInputs = [ gettext pkg-config which ];
  
negative.code:     done
  
      popd
      runHook postCheck
    '';
  
    postInstall = ''
      rm -f $out/bin/dvdisaster-uninstall.sh
      mkdir -pv $out/share/applications
      cp contrib/dvdisaster.desktop $out/share/applications/
  
  