optional_depends linux-pam \
                 "--enable-plugin-auth-pam" \
                 "--disable-plugin-auth-pam" \
                 "to build auth-pam plugin" &&

optional_depends pkcs11-helper \
                 "--enable-pkcs11" \
                 "--disable-pkcs11" \
                 "for PKCS#11 support" &&

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

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

optional_depends iproute2 \
                 "--enable-iproute2" \
                 "--disable-iproute2" \
                 "for iproute2 support" &&

optional_depends libselinux \
                 "--enable-selinux" \
                 "--disable-selinux" \
                 "for SELinux support" &&

suggest_depends SYSTEM-LOGGER "" "" "for logging through syslog"

.