anchor.diff:  
     buildInputs = [ openssl zlib pcre libxml2 libxslt ] ++ stdenv.lib.optional fullWebDAV expat;
   
  +  patches = if syslog then [ "${syslog-ext}/syslog_1.4.0.patch" ] else [];
  +
     configureFlags = [
       "--with-http_ssl_module"
       "--with-http_xslt_module"
  
positive.code: { stdenv, fetchurl, fetchgit, openssl, zlib, pcre, libxml2, libxslt, expat, fullWebDAV ? false }:
  
  let
    dav-ext = fetchgit {
      url = git://github.com/arut/nginx-dav-ext-module.git;
      rev = "54cebc1f21fc13391aae692c6cce672fa7986f9d";
      sha256 = "1dvpq1fg5rslnl05z8jc39sgnvh3akam9qxfl033akpczq1bh8nq";
    };
  in
  
  
negative.code:     "--with-http_secure_link_module"
      # Install destination problems
      # "--with-http_perl_module"
    ] ++ stdenv.lib.optional fullWebDAV "--add-module=${dav-ext}"
      ++ stdenv.lib.optional syslog "--add-module=${syslog-ext}";
  
    preConfigure = ''
      export NIX_CFLAGS_COMPILE="$NIX_CFLAGS_COMPILE -I${libxml2}/include/libxml2"
  