anchor.diff:  
     tracking = melpaBuild rec {
       pname   = "tracking";
  -    version = "1.5";
  -    src = fetchFromGitHub {
  -      owner  = "jorgenschaefer";
  -      repo   = "circe";
  -      rev    = "v${version}";
  -      sha256 = "08dsv1dzgb9jx076ia7xbpyjpaxn1w87h6rzlb349spaydq7ih24";
  -    };
  +    version = circe.version;
  +    src     = circe.src;
       packageRequires = [ shorten ];
  -    fileSpecs = [ "lisp/tracking*.el" ];
  +    fileSpecs = [ "tracking.el" ];
       meta = {
         description = "Register buffers for user review library for Emacs";
         license = gpl3Plus;
  
positive.code:     };
    };
  
    shorten = melpaBuild rec {
      pname   = "shorten";
      version = "1.5";
      src = fetchFromGitHub {
        owner  = "jorgenschaefer";
        repo   = "circe";
        rev    = "v${version}";
        sha256 = "08dsv1dzgb9jx076ia7xbpyjpaxn1w87h6rzlb349spaydq7ih24";
      };
      fileSpecs = [ "lisp/shorten*.el" ];
      meta = {
        description = "String shortening to unique prefix library for Emacs";
        license = gpl3Plus;
  
negative.code: 
    magit = melpaBuild rec {
      pname   = "magit";
      version = "2.3.1";
      src = fetchFromGitHub {
        owner  = pname;
        repo   = pname;
        rev    = version;
        sha256 = "01x9kahr3szzc00wlfrihl4x28yrq065fq4rpzx9dxiksayk24pd";
      };
      packageRequires = [ dash git-commit magit-popup with-editor ];
      fileSpecs = [ "lisp/magit-utils.el"
  