anchor.diff:      rev = "165affd9741f0e30c4c8225da5e487d33832aca3";
       sha256 = "14dkkafjnbapp6jnvrjg9ip46j00cr8pqc2g7374z9aj7hrvdvhs";
     };
  +
  +  moreheaders-ext = fetchgit {
  +    url = https://github.com/agentzh/headers-more-nginx-module.git;
  +    rev = "refs/tags/v0.23";
  +    sha256 = "12pbjgsxnvcf2ff2i2qdn39q4cm5czlgrng96j8ml4cgxvnbdh39";
  +  };
   in
   
   stdenv.mkDerivation rec {
  
positive.code: { stdenv, fetchurl, fetchgit, openssl, zlib, pcre, libxml2, libxslt, expat
  , rtmp ? false
  , fullWebDAV ? false
  , syslog ? false}:
  
  let
    version = "1.4.4";
  
negative.code:     # "--with-http_perl_module"
    ] ++ stdenv.lib.optional rtmp "--add-module=${rtmp-ext}"
      ++ stdenv.lib.optional fullWebDAV "--add-module=${dav-ext}"
      ++ stdenv.lib.optional syslog "--add-module=${syslog-ext}"
      ++ stdenv.lib.optional moreheaders "--add-module=${moreheaders-ext}";
  
    preConfigure = ''
      export NIX_CFLAGS_COMPILE="$NIX_CFLAGS_COMPILE -I${libxml2}/include/libxml2"
  