anchor.diff:  { stdenv
  +, fetchFromGitHub
   , fetchurl
  +, lib
   
   , kernel
   
  
positive.code: }:
  
  let
    inherit (stdenv.lib)
      optionalString;
  
    tarballUrls = version: [
      "http://nwl.cc/pub/cryptodev-linux/cryptodev-linux-${version}.tar.gz"
      "http://download.gna.org/cryptodev-linux/cryptodev-linux-${version}.tar.gz"
    ];
  
    version = "1.9";
  in
  stdenv.mkDerivation rec {
    name = "cryptodev-linux-${version}";
  
    src = fetchurl {
      urls = tarballUrls version;
      multihash = "QmZqPXZDUZdsjnkx7wbYUirnzj6ajmGTA1DzMXe9gtXU2a";
      hashOutput = false;
      sha256 = "9f4c0b49b30e267d776f79455d09c70cc9c12c86eee400a0d0a0cd1d8e467950";
    };
  
    # If we are only building headers, just do that
    buildCommand = optionalString onlyHeaders ''
      unpackPhase
      mkdir -p $out/include/crypto
      cp */crypto/cryptodev.h $out/include/crypto
    '';
  
    preBuild = optionalString (!onlyHeaders) ''
  
negative.code:   ];
  
    passthru = {
      srcVerification =
        let
          version = "1.10";
        in
        fetchFromGitHub {
          version = 6;
          owner = "cryptodev-linux";
          repo = "cryptodev-linux";
          rev = "cryptodev-linux-${version}";
          sha256 = "7bf74db0e48741659c1f55eac5e429fd53d06dff19daa3e447fe964594d3ada9";
        };
    };
  
    meta = with lib; {
      description = "Device that allows access to Linux kernel cryptographic drivers";
      homepage = http://home.gna.org/cryptodev-linux/;
      license = licenses.gpl2Plus;
  