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: 
    buildInputs =
      [ openssl zlib pcre libxml2 libxslt gd geoip
      ] ++ optional fullWebDAV expat;
  
    patches = if syslog then [ "${syslog-ext}/syslog-1.5.6.patch" ] else [];
  
  
negative.code: { stdenv, fetchurl, fetchgit, openssl, zlib, pcre, libxml2, libxslt, expat
  , gd, geoip, luajit
  , rtmp ? false
  , fullWebDAV ? false
  , syslog ? false
  , moreheaders ? false
  , echo ? false
  , ngx_lua ? false }:
  
  with stdenv.lib;
  
  