anchor.diff:      "--disable-fixed-rrset"
       "--enable-rpz-nsip"
       "--enable-rpz-nsdname"
  -    "--enable-filter-aaaa"
       "--with-docbook-xsl=${docbook-xsl-ns}/share/xsl/docbook"
       "--with-idn=${idnkit}"
       "--without-atf"
  
positive.code:     libxml2
      lmdb
      ncurses
      openssl_1-0-2
      pythonPackages.python
      pythonPackages.ply
      readline
  
negative.code:     optionals
      optionalString;
  
    version = "9.12.0";
  in
  stdenv.mkDerivation rec {
    name = "bind${optionalString (suffix != "") "-${suffix}"}-${version}";
  
    src = fetchurl {
      url = "https://ftp.isc.org/isc/bind9/${version}/bind-${version}.tar.gz";
      multihash = "QmUxfY25Ra6LbJyhyakP61whVEdGghRKH8Lj7pN9KBwreD";
      hashOutput = false;
      sha256 = "29870e9bf9dcc31ead3793ca754a7b0236a0785a7a9dc0f859a0bc42e19b3c82";
    };
  
    nativeBuildInputs = [
  