anchor.diff:        releaseTools.nixBuild {
           name = "strategoxt";
           src = tarball;
  - 
           buildInputs = defaultBuildInputs systemPkgs ;
  -
         };
   
     } ;
  
positive.code:       buildInputs = defaultBuildInputs pkgs ;
      };
  
      defaultBuildInputs = pkgs :
        [ pkgs.pkgconfig
          pkgs.aterm
          pkgs.strategoPackages017.sdf
          pkgs.getopt
        ];
  
      defaultSvnBuildInputs = pkgs :
        [ pkgs.autoconf
          pkgs.automake19x
          pkgs.libtool
        ] ++ defaultBuildInputs pkgs;
  
    makeStrategoXTTarball = name : baseline :
      pkgs.releaseTools.makeSourceTarball {
        name = name;
        version = builtins.readFile ./version;
  
negative.code:       dontInstall = false;
        tarballs = "*.tar.gz";
  
        inherit officialRelease, useTempPrefix;
      };
  
    svn_tarball_run1 = 
      makeStrategoXTTarball {
        name = "strategoxt-tarball1" ;
        baseline = strategoxtBaseline ;
      } ;
  
    svn_tarball_run2 = 
      makeStrategoXTTarball {
        name = "strategoxt-tarball2" ;
        baseline = svn_tarball_run1 ;
      } ;
  
    systemPkgs = import nixpkgs {inherit system;};
  
    jobs = rec {
  
      tarball = 
        makeStrategoXTTarball {
        name = "strategoxt-tarball2";
        baseline = svn_tarball_run2;
        useTempPrefix = true;
      };
  
      build =
        { tarball ? jobs.tarball
  