anchor.diff:    }:
   
   let
  -  optional = stdenv.lib.optional;
  -  version = "3.31";
  -  name = "libreswan-${version}";
     binPath = stdenv.lib.makeBinPath [
       bash iproute iptables procps coreutils gnused gawk nss.tools which python
     ];
  
positive.code:   nativeBuildInputs = [ makeWrapper pkgconfig ];
    buildInputs = [ bash iproute iptables systemd coreutils gnused gawk gmp unbound bison flex pam libevent
                    libcap_ng curl nspr nss python ldns ]
                  ++ optional docs xmlto
                  ++ optional stdenv.isLinux libselinux;
  
    prePatch = ''
      # Correct bash path
  
negative.code: assert docs -> xmlto != null;
  assert stdenv.isLinux -> libselinux != null;
  
  stdenv.mkDerivation rec {
    pname = "libreswan";
    version = "3.32";
  
    src = fetchurl {
      url = "https://download.libreswan.org/${pname}-${version}.tar.gz";
      sha256 = "0bj3g6qwd3ir3gk6hdl9npy3k44shf56vcgjahn30qpmx3z5fsr3";
    };
  
    # These flags were added to compile v3.18. Try to lift them when updating.
  