anchor.diff:  
     nativeBuildInputs = [ pkgconfig libtool ];
     buildInputs = [
  -    curl python munge perl pam openssl
  +    curl python munge perl pam openssl zlib
         mysql.connector-c ncurses gtk2 lz4
         lua hwloc numactl readline freeipmi
     ] ++ stdenv.lib.optionals enableX11 [ libssh2 xorg.xauth ];
  
positive.code:   configureFlags = with stdenv.lib;
      [ "--with-freeipmi=${freeipmi}"
        "--with-hwloc=${hwloc.dev}"
        "--with-lz4=${lz4}"
        "--with-munge=${munge}"
        "--with-ssl=${openssl.dev}"
        "--sysconfdir=/etc/slurm"
      ] ++ (optional (gtk2 == null)  "--disable-gtktest")
        ++ (optional enableX11 "--with-libssh2=${libssh2.dev}");
  
negative.code: { stdenv, fetchFromGitHub, pkgconfig, libtool, curl
  , python, munge, perl, pam, openssl, zlib
  , ncurses, mysql, gtk2, lua, hwloc, numactl
  , readline, freeipmi, libssh2, xorg, lz4
  # enable internal X11 support via libssh2
  