anchor.diff:    rabbitmq = pkgs.callPackage ./rabbitmq { inherit erlang; };
   
     solr = pkgs.callPackage ./solr {};
  +
  +  #
  +  # python
  +  #
  +
  +  heavy-sync = with pythonPackages; pkgs.callPackage ./heavy-sync {
  +    inherit boto;
  +    inherit gcs-oauth2-boto-plugin;
  +    inherit sqlite3;
  +  };
  +
  +  helper = pythonPackages.buildPythonPackage rec {
  +    name = "helper-2.4.1";
  +
  +    propagatedBuildInputs = with pythonPackages; [ pyyaml ];
  +    buildInputs = with pythonPackages; [ mock ];
  +
  +    src = fetchurl {
  +      url = "https://pypi.python.org/packages/source/h/helper/${name}.tar.gz";
  +      md5 = "e7146c95bbd96a12df8d737a16dca3a7";
  +    };
  +
  +    meta = with stdenv.lib; {
  +      description = "Helper";
  +      homepage = https://helper.readthedocs.org;
  +      license = licenses.bsd3;
  +    };
  +  };
  +
  +  newrelic-python = import ./newrelic-python { inherit pkgs; };
   
     statsd = pythonPackages.buildPythonPackage rec {
       name = "statsd-3.0.1";
  
positive.code: { pkgs ? import <nixpkgs> { system = "x86_64-linux"; config.allowUnfree = true; }
  , ...
  }:
  
  let
    inherit (pkgs)
  
negative.code:     stdenv fetchurl;
    inherit (lib) overrideDerivation;
  in rec {
    couchbase = pkgs.callPackage ./couchbase {};
  
    damemtop = pkgs.writeScriptBin "damemtop" ''
  