optional_depends glib2    "--with-glib" "--without-glib" "GLib support" &&
#optional_depends libev    "--with-libev" "--without-libev" "LIBEV support" &&
optional_depends libevent "--with-libevent" "--without-libevent" "LIBEVENT support" &&
optional_depends tevent   "--with-tevent" "--without-tevent" "TEVENT support"
