anchor.diff:  
     buildInputs = [ openssl expat libevent python ];
   
  -  postPatch = ''substituteInPlace Makefile.in \
  -    --replace "\$(DESTDIR)\$(PYTHON_SITE_PKG)" "$out/${python.sitePackages}" \
  -    --replace "\$(LIBTOOL) --mode=install cp _unbound.la" "cp _unbound.la"
  +  postPatch = ''
  +    substituteInPlace Makefile.in \
  +      --replace "\$(DESTDIR)\$(PYTHON_SITE_PKG)" "$out/${python.sitePackages}" \
  +      --replace "\$(LIBTOOL) --mode=install cp _unbound.la" "cp _unbound.la"
     '';
   
     preConfigure = "export PYTHON_VERSION=${python.pythonVersion}";
  
positive.code:     cp .libs/_unbound.so .libs/libunbound.so* $out/${python.sitePackages}
      substituteInPlace _unbound.la \
        --replace "-L.libs $PWD/libunbound.la" "-L$out/${python.sitePackages}"
      '';
  
    installFlags = [
      "configfile=\${out}/etc/unbound/unbound.conf"
  
negative.code: 
  let
    inherit (pythonPackages) python;
  in
  stdenv.mkDerivation rec {
    pname = "pyunbound";
    version = "1.13.1";
  
    src = fetchurl {
      url = "https://nlnetlabs.nl/downloads/unbound/unbound-${version}.tar.gz";
      sha256 = "sha256-hQTZe4/FvYlzRcldEW4O4N34yP+ZWQqytL0TJ4yfULg=";
    };
  
  