dovecot build error (no libsasl2.la)

I'm trying to build dovecot and there's no libsasl2.la. It errors with "/usr/lib64/libsasl2.la not found". Trying to create a syslink to libsasl2.3.0.0 and rebuilding results in "libsasl2.la is not a valid libtool archive".

Any ideas on how to build dovecot on slackware64-current?

Thanks,
Jim