optional_depends  openssl                                                    \
                  ""                                                         \
                  "--disable-crypto --disable-ssl"                           \
                  "for crypto and key exchange support (highly recommended)" &&

optional_depends  lzo                                                        \
                  ""                                                         \
                  "--disable-lzo"                                            \
                  "for LZO compression (highly recommended)"                 &&

optional_depends  SYSTEM-LOGGER                                              \
                  ""                                                         \
                  ""                                                         \
                  "for logging through syslog"
