anchor.diff:        mkdir -p $out/empty
       '';
   
  +  enableParallelBuilding = true;
  +
     postInstall =
       ''
         # Install ssh-copy-id, it's very useful.
  
positive.code:       export NIX_LDFLAGS="$NIX_LDFLAGS -lgcc_s"
      '';
  
    patches = [
      ./locale_archive.patch
      (fetchurl {
        name = "CVE-2014-2653.patch";
        url = "http://anonscm.debian.org/gitweb/?p=pkg-ssh/openssh.git;a=blobdiff_plain;"
          + "f=sshconnect.c;h=324f5e0a396a4da9885d121bbbef87f6ccf2b149;"
          + "hp=87c3770c0fd5c7ff41227c45b4528985eaea54a6;hb=63d5fa28e16d96db6bac2dbe3fcecb65328f8966;"
          + "hpb=9cbb60f5e4932634db04c330c88abc49cc5567bd";
        sha256 = "160c434igl2r8q4cavhdlwvnbqizx444sjrhg98f997pyhz524h9";
      })
    ];
  
    buildInputs = [ zlib openssl libedit pkgconfig pam ]
      ++ stdenv.lib.optional withKerberos [ kerberos ];
  
negative.code: in
  
  stdenv.mkDerivation rec {
    name = "openssh-6.7p1";
  
    src = fetchurl {
      url = "http://ftp.nluug.nl/pub/OpenBSD/OpenSSH/portable/${name}.tar.gz";
      sha256 = "01smf9pvn2sk5qs80gkmc9acj07ckawi1b3xxyysp3c5mr73ky5j";
    };
  
    prePatch = stdenv.lib.optionalString hpnSupport
  