anchor.diff:  { stdenv, fetchurl, kernel, alsaLib }:
   
  +with stdenv.lib;
  +
   # The Magewell Pro Capture drivers are not supported for kernels older than 3.2
  -assert stdenv.lib.versionAtLeast kernel.version "3.2.0";
  +assert versionAtLeast kernel.version "3.2.0";
   
   # this package currently only supports x86 and x86_64, as I have no ARM device to test on
   assert (stdenv.system == "x86_64-linux") || (stdenv.system == "i686-linux");
  
positive.code:       "$out"/bin/mwcap-info
    '';
  
    meta = with stdenv.lib; {
      homepage = http://www.magewell.com/;
      description = "Linux driver for the Magewell Pro Capture family";
      license = licenses.unfreeRedistributable;
  
negative.code:   if stdenv.is64bit then "64"
    else "32";
  
    libpath = makeLibraryPath [ stdenv.cc.cc stdenv.glibc alsaLib ];
  
  in
  stdenv.mkDerivation rec {
  