Enabling cyrus-sasl for gssapi

[Mark Foley]

I would like to enable saslauthd for GSSAPI for sendmail authentication.  I am
running Samba4 4.4.16 on Slackware64 14.2.  Samaba4 includes Heimdal kerberos. 
The Dovecot mail server authenticates domain users using the Thunderbird email
client via GSSAPI, so that indicates to me that it is doable.  My current
saslauthd has:

$ saslauthd -v
saslauthd 2.1.26
authentication mechanisms: getpwent rimap shadow

So, I believe this means I have to build sasl from source to enable GSSAPI.

I downloaded the 2.1.26 tarball from ftp://ftp.cyrusimap.org/cyrus-sasl/. I did:

$ ./configure --enable-gssapi --with-gss_impl=heimdal
$ make
$ saslauthd/saslauthd -v
saslauthd 2.1.26
authentication mechanisms: getpwent rimap shadow

Despite specifying --enable-gssapi the new binary does not show gssapi as a
mechanism. Why?

Thanks, Mark