anchor.diff:  # if you update, also bump <nixpkgs/pkgs/development/python-modules/libvirt/default.nix> and SysVirt in <nixpkgs/pkgs/top-level/perl-packages.nix>
   let
     buildFromTarball = stdenv.isDarwin;
  -  # libvirt hardcodes the binary name 'ebtables', but in nixpkgs the ebtables
  -  # binary we want to use is named 'ebtables-legacy'.
  -  # Create a derivation to alias the binary name so that libvirt can find the right one, and use that below.
  -  ebtables-compat = stdenv.mkDerivation {
  -    pname = "ebtables-compat";
  -    version = ebtables.version;
  -    src = null;
  -    buildInputs = [ ebtables ];
  -    buildCommand = ''
  -      mkdir -p $out/bin
  -      ln -sf ${ebtables}/bin/ebtables-legacy $out/bin/ebtables
  -    '';
  -  };
   in
   stdenv.mkDerivation rec {
     pname = "libvirt";
  
positive.code: , gettext
  , libtasn1
  , iptables
  , ebtables
  , libgcrypt
  , yajl
  , pmutils
  
negative.code: 
    postInstall =
      let
        binPath = [ iptables iproute2 pmutils numad numactl bridge-utils dmidecode dnsmasq ] ++ optionals enableIscsi [ openiscsi ];
      in
      ''
          substituteInPlace $out/libexec/libvirt-guests.sh \
  