It is something I have stumbled upon frequently with Ray-V's slackbuilds, and for some reason they refuse to change this behaviour.

Anyway, when building tdebase, you need to set the WITH_SASL flag.

Go to Core/tdebase and open tdebase.SlackBuild in your preferred text editor. Find the line that says -DWITH_SASL="OFF" and replace OFF with ON. Save and rebuild just tdebase normally (via BUILD-TDE.sh)

Hope this helps.

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Philippe