anchor.diff:      ++ optional syslog "--add-module=${syslog-ext}"
       ++ optional moreheaders "--add-module=${moreheaders-ext}"
       ++ optional echo "--add-module=${echo-ext}"
  +    ++ optional ngx_lua "--add-module=${develkit-ext} --add-module=${lua-ext}"
       ++ optional (elem stdenv.system (with platforms; linux ++ freebsd)) "--with-file-aio";
   
   
  
positive.code: { stdenv, fetchurl, fetchgit, openssl, zlib, pcre, libxml2, libxslt, expat
  , gd, geoip
  , rtmp ? false
  , fullWebDAV ? false
  , syslog ? false
  , moreheaders ? false
  , echo ? false }:
  
  with stdenv.lib;
  
  
negative.code:     rev = "refs/tags/v0.53";
      sha256 = "90d4e3a49c678019f4f335bc18529aa108fcc9cfe0747ea4e2f6084a70da2868";
    };
  
    develkit-ext = fetchgit {
      url = https://github.com/simpl/ngx_devel_kit.git;
      rev = "refs/tags/v0.2.19";
      sha256 = "169m6gsa5b6zh1ws8qx2k7dbswld1zmhm4dh57qka0h07gs5dqjg";
    };
  
    lua-ext = fetchgit {
      url = https://github.com/openresty/lua-nginx-module.git;
      rev = "refs/tags/v0.9.11";
      sha256 = "0y7238bvb907n7fsz5sivxbhfz2xnf4f0lzwk3k3h9j20fsyvwqq";
    };
  
  in
  
  stdenv.mkDerivation rec {
  