anchor.diff:  
     meta = {
       homepage = http://www.memtest.org/;
  -    description = "A tool to detect memory errors, fork from memtest86";
  +    description = "A tool to detect memory errors";
  +    license = stdenv.lib.licenses.gpl2;
     };
   }
  
positive.code:   '';
  
    NIX_CFLAGS_COMPILE = "-I.";
    
    installPhase = ''
      mkdir -p $out
      cp memtest.bin $out/
  
negative.code: { stdenv, fetchurl }:
  
  stdenv.mkDerivation rec {
    name = "memtest86+-5.01";
  
    src = fetchurl {
      url = "http://www.memtest.org/download/5.01/${name}.tar.gz";
      sha256 = "0fch1l55753y6jkk0hj8f6vw4h1kinkn9ysp22dq5g9zjnvjf88l";
    };
  
    preBuild = ''
  