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:   if stdenv.is64bit then "64"
    else "32";
  
    libpath = stdenv.lib.makeLibraryPath [ stdenv.cc.cc stdenv.glibc alsaLib ];
  
  in
  stdenv.mkDerivation rec {
  
negative.code:     sha256 = "1arwnwrq52rs8g9zfxw8saip40vc3201sf7qnbqd2p23h8vzwb8i";
    };
  
    patches = [] ++ optional (versionAtLeast kernel.version "4.13") ./linux_4_13_fix.patch;
  
    preConfigure =
    ''
  