anchor.diff: -{ lib, stdenv, fetchurl, makeWrapper, pkg-config, nss, nspr, libqb
  +{ lib, stdenv, fetchurl, makeWrapper, pkg-config, kronosnet, nss, nspr, libqb
   , dbus, rdma-core, libstatgrab, net-snmp
   , enableDbus ? false
   , enableInfiniBandRdma ? false
  
positive.code:     "LOGROTATEDIR=$(out)/etc/logrotate.d"
    ];
  
    preConfigure = optionalString enableInfiniBandRdma ''
      # configure looks for the pkg-config files
      # of librdmacm and libibverbs
  
negative.code: 
  stdenv.mkDerivation rec {
    pname = "corosync";
    version = "3.1.2";
  
    src = fetchurl {
      url = "http://build.clusterlabs.org/corosync/releases/${pname}-${version}.tar.gz";
      sha256 = "sha256-eAypUbDeGa3GKF/wJ602dyTW5FlkvjWeCRXT6h0d4zw=";
    };
  
    nativeBuildInputs = [ makeWrapper pkg-config ];
  
    buildInputs = [
      kronosnet nss nspr libqb
    ] ++ optional enableDbus dbus
      ++ optional enableInfiniBandRdma rdma-core
      ++ optional enableMonitoring libstatgrab
  