anchor.diff: -{ lib, stdenv, fetchurl, libpcap, bison, flex, cyrus_sasl, tcp_wrappers, pkg-config, perl }:
  +{ lib, stdenv, fetchurl, libpcap, bison, flex, cyrus_sasl, tcp_wrappers, pkg-config, perl, libtirpc, libnsl }:
   
   stdenv.mkDerivation rec {
     pname = "argus-clients";
  
positive.code:   configureFlags = [ "--with-perl=${perl}/bin/perl" ];
  
    nativeBuildInputs = [ pkg-config ];
    buildInputs = [ libpcap bison cyrus_sasl tcp_wrappers flex ];
  
    meta = with lib; {
      description = "Clients for ARGUS";
  
negative.code:     sha256 = "1c9vj6ma00gqq9h92fg71sxcsjzz912166sdg90ahvnmvmh3l1rj";
    };
  
    NIX_CFLAGS_COMPILE = [ "-I${libtirpc.dev}/include/tirpc" ];
  
    postPatch = ''
      for file in ./examples/*/*.pl; do
        substituteInPlace $file \
          --subst-var-by PERLBIN ${perl}/bin/perl
  