anchor.diff:  , pkg-config
   , expat
   , enableSystemd ? stdenv.isLinux && !stdenv.hostPlatform.isStatic
  -, systemd
  +, systemdMinimal
   , audit
   , libapparmor
   , dbus
  
positive.code:     "--with-systemduserunitdir=${placeholder "out"}/etc/systemd/user"
    ] ++ lib.optional (!x11Support) "--without-x"
    ++ lib.optionals stdenv.isLinux [ "--enable-apparmor" "--enable-libaudit" ]
    ++ lib.optionals enableSystemd [ "SYSTEMCTL=${systemd}/bin/systemctl" ];
  
    NIX_CFLAGS_LINK = lib.optionalString (!stdenv.isDarwin) "-Wl,--as-needed";
  
  
negative.code:       libX11
        libICE
        libSM
      ]) ++ lib.optional enableSystemd systemdMinimal
      ++ lib.optionals stdenv.isLinux [ audit libapparmor ];
    # ToDo: optional selinux?
  
  