anchor.diff:  
   stdenv.mkDerivation rec {
     pname = "rng-tools";
  -  version = "6.7";
  +  version = "6.8";
   
     src = fetchFromGitHub {
       owner = "nhorman";
       repo = "rng-tools";
       rev = "v${version}";
  -    sha256 = "19f75m6mzg8h7b4snzg7d6ypvkz6nq32lrpi9ja95gqz4wsd18a5";
  +    sha256 = "1clm9i9xg3j79q0d6vinn6dx0nwh1fvzcmkqpcbay7mwsgkknvw2";
     };
   
     postPatch = ''
  -    cp README.md README
  -
       ${optionalString withPkcs11 ''
         substituteInPlace rngd.c \
           --replace /usr/lib64/opensc-pkcs11.so ${opensc}/lib/opensc-pkcs11.so
  
positive.code:     (withFeature   withPkcs11        "pkcs11")
    ];
  
    buildInputs = [ sysfsutils ]
      ++ optionals withGcrypt        [ libgcrypt ]
      ++ optionals withJitterEntropy [ jitterentropy ]
      ++ optionals withNistBeacon    [ curl libxml2 openssl ]
      ++ optionals withPkcs11        [ libp11 openssl ];
  
    # This shouldn't be necessary but is as of 6.7
    NIX_LDFLAGS = optionalString withPkcs11 "-lcrypto";
  
    enableParallelBuilding = true;
  
    # For cross-compilation
    makeFlags = [ "AR:=$(AR)" ];
  
    meta = {
      description = "A random number generator daemon";
      homepage = https://github.com/nhorman/rng-tools;
      license = licenses.gpl2Plus;
      platforms = platforms.linux;
      maintainers = with maintainers; [ johnazoidberg ];
    };
  }
  
negative.code: { stdenv, fetchFromGitHub, libtool, autoreconfHook, pkgconfig
  , sysfsutils
  , argp-standalone
    # WARNING: DO NOT USE BEACON GENERATED VALUES AS SECRET CRYPTOGRAPHIC KEYS
    # https://www.nist.gov/programs-projects/nist-randomness-beacon
  , curl ? null, libxml2 ? null, openssl ? null, withNistBeacon ? false
    # Systems that support RDRAND but not AES-NI require libgcrypt to use RDRAND as an entropy source
  , libgcrypt ? null, withGcrypt ? true
  , jitterentropy ? null, withJitterEntropy ? true
  , libp11 ? null, opensc ? null, withPkcs11 ? true
  }:
  
  