Please run the SlackBuild script as root user.

An optional cron script to keep the framework up to date is
distributed inside the /usr/doc/metasploit-${VERSION} directory and
it's called "msfupdate.sh", there also is a logrotate config file
called "msfupdate.logrotate" which can be useful.

Inside the /usr/doc/metasploit-${VERSION} directory you'll also find a
bash-completion script for msfvenom, courtesy of kali linux.