anchor.diff:  { stdenv
  -, fetchurl
  +, autoreconfHook
  +, fetchFromGitHub
   
   , acl
   , attr
  
positive.code:   configureFlags = [
      "--with-zlib"
      "--with-bz2lib"
      "--without-lzmadec"
      "--with-iconv"
      "--with-lz4"
      "--with-lzma"
  
negative.code: }:
  
  stdenv.mkDerivation rec {
    name = "libarchive-2017-01-04";
  
    src = fetchFromGitHub {
      version = 2;
      owner = "libarchive";
      repo = "libarchive";
      rev = "98eb6b0bf3624e1c4f05c5cf18c59c25b2ff2bb7";
      sha256 = "e1545e7e1940c98214720c21a8cc089b263181d228c39a7c680b7d2cdb6a244a";
    };
  
    nativeBuildInputs = [
      autoreconfHook
    ];
  
    buildInputs = [
      acl
  