anchor.diff:        --with-libedit=yes
         --disable-strip
         ${if pam != null then "--with-pam" else "--without-pam"}
  -      ${if etcDir != null then "--sysconfdir=${etcDir}" else ""}
  -      ${if withKerberos  then "--with-kerberos5=${kerberos}" else ""}
  +      ${optionalString (etcDir != null) "--sysconfdir=${etcDir}"}
  +      ${optionalString withKerberos "--with-kerberos5=${kerberos}"}
       '';
   
     preConfigure =
  
positive.code:     url = mirror://sourceforge/hpnssh/openssh-6.3p1-hpnssh14v2.diff.gz;
      sha256 = "1jldqjwry9qpxxzb3mikfmmmv90mfb7xkmcfdbvwqac6nl3r7bi3";
    };
  
  in
  
  stdenv.mkDerivation rec {
    name = "openssh-6.4p1";
  
    src = fetchurl {
      url = "ftp://ftp.nl.uu.net/pub/OpenBSD/OpenSSH/portable/${name}.tar.gz";
      sha256 = "1lkmi7v83qvpcc04qrrqk4k7mafnmwxkfk1ccsisw51va4bgcc2m";
    };
  
    prePatch = stdenv.lib.optionalString hpnSupport
  
negative.code: 
    installTargets = "install-nosysconf";
  
    meta = with stdenv.lib; {
      homepage = "http://www.openssh.org/";
      description = "An implementation of the SSH protocol";
      license = "bsd";
      platforms = platforms.unix;
      maintainers = with maintainers; [ eelco ];
    };
  }
  