optional_depends LINUX-PAM-HEADERS \
    "--with-pam" \
    "--without-pam" \
    "PAM support" &&
optional_depends libupnp \
    "--with-upnp" \
    "--without-upnp" \
    "upnp support" &&
optional_depends tcp_wrappers \
    "--enable-libwrap" \
    "--disable-libwrap" \
    "tcp wrapper support" &&
optional_depends gssapi \
    "--with-gssapi" \
    "--without-gssapi" \
    "gssapi support"
