anchor.diff:  
       build =
         { system ? "i686-linux" 
  -      , tarball ? jobs.tarball {}
         }:
   
         let pkgs = import nixpkgs {inherit system;};
  
positive.code: { nixpkgs ? ../nixpkgs
    , webdslEditor ? { outPath = ../../webdsl-editor ; rev = 1234; }
    , hydraConfig ? { outPath = ../../hydra-config ; rev = 1234; } 
  }:
  
  let
  
negative.code:       };
  
      buildJavaZip = 
        pkgs.stdenv.mkDerivation {
          name = "webdsl-java.zip"; 
          buildInputs = [pkgs.zip]; 
  