The tripwire database isn't created on install, thus root gets sent this
From root Thu Aug 10 11:14:24 2000
Date: Thu, 10 Aug 2000 11:14:23 -0500
From: email@example.com (Anacron)
Subject: Anacron job 'cron.daily'
**** Error: Tripwire database for localhost.localdomain not found.
**** Run /etc/tripwire/twinstall.sh and/or tripwire --init. ****
The database cannot be generated automatically. It is cryptographically signed,
and needs to be signed using your site-specific pass-phrase. The tw-install
script is used to set this.