optional_depends  "gnutls"             \
                  "--with-gnutls"      \
                  "--without-gnutls"   \
                  "for GnuTLS support" &&

optional_depends  "libgcrypt"                                 \
                  " --enable-cram-md5   --enable-digest-md5"  \
                  "--disable-cram-md5  --disable-digest-md5"  \
                  "support for CRAM-MD5 and DIGEST-MD5"       &&

optional_depends  "gss"                 \
                  " --enable-gssapi"    \
                  "--disable-gssapi"    \
                  "support for GSSAPI"  &&

optional_depends  "libntlm"                                      \
                  " --enable-ntlm"                               \
                  "--disable-ntlm"                               \
                  "support for Microsoft's NTLM authentication"
