anchor.diff:      then pname
       else ename;
   
  -  melpa = fetchFromGitHub {
  +  packageBuild = fetchFromGitHub {
       owner = "melpa";
  -    repo = "melpa";
  -    rev = "7103313a7c31bb1ebb71419e365cd2e279ee4609";
  -    sha256 = "0m10f83ix0mzjk0vjd4kkb1m1p4b8ha0ll2yjsgk9bqjd7fwapqb";
  +    repo = "package-build";
  +    rev = "0a22c3fbbf661822ec1791739953b937a12fa623";
  +    sha256 = "0dpy5p34il600sc8ic5jdgb3glya9si3lrvhxab0swks8fdydjgs";
     };
   
     elpa2nix = ./elpa2nix.el;
  
positive.code:       cp "$recipe" "$NIX_BUILD_TOP/recipes/$ename"
      fi
  
      ln -s "$melpa/package-build" "$NIX_BUILD_TOP/package-build"
  
      mkdir -p "$NIX_BUILD_TOP/packages"
    '';
  
negative.code:     cd "$NIX_BUILD_TOP"
  
      emacs --batch -Q \
          -L "$NIX_BUILD_TOP/package-build" \
          -l "$melpa2nix" \
          -f melpa2nix-build-package \
          $ename $version
  