anchor.diff:  
     buildInputs =
       [ openssl zlib pcre libxml2 libxslt gd geoip
  -    ] ++ stdenv.lib.optional fullWebDAV expat;
  +    ] ++ optional fullWebDAV expat;
   
     patches = if syslog then [ "${syslog-ext}/syslog-1.5.6.patch" ] else [];
   
  
positive.code: , rtmp ? false
  , fullWebDAV ? false
  , syslog ? false
  , moreheaders ? false}:
  
  let
    version = "1.6.0";
  
negative.code:     "--with-ipv6"
      # Install destination problems
      # "--with-http_perl_module"
    ] ++ optional rtmp "--add-module=${rtmp-ext}"
      ++ optional fullWebDAV "--add-module=${dav-ext}"
      ++ optional syslog "--add-module=${syslog-ext}"
      ++ optional moreheaders "--add-module=${moreheaders-ext}"
      ++ optional echo "--add-module=${echo-ext}"
      ++ optional (elem stdenv.system (with platforms; linux ++ freebsd)) "--with-file-aio";
  
  
    additionalFlags = optionalString stdenv.isDarwin "-Wno-error=deprecated-declarations";
  
    preConfigure = ''
      export NIX_CFLAGS_COMPILE="$NIX_CFLAGS_COMPILE -I${libxml2}/include/libxml2 $additionalFlags"
  