Since there is no OpenBSD package for the dirvish backup system, here are my installation steps:

1. Download tgz from https://dirvish.org/.
2. Install packages for perl modules specified in INSTALL:
   • POSIX - already installed when I checked; haven't checked a base system
   • Getopt::Long - already installed when I checked; haven't checked a base system
   • Time::ParseDate - p5-Time-modules
   • Time::Period - p5-Time-Period
3. $ tar -xzvf dirvish-1.2.1.tgz
4. $ cd dirvish-1.2.1
5. $ doas sh install.sh

perl to use (/usr/bin/perl) 
What installation prefix should be used? () /usr/local
Directory to install executables? (/usr/local/sbin) 
Directory to install MANPAGES? (/usr/local/man) 
Configuration directory (/etc/dirvish)

1. Configure /etc/dirvish/master.conf
2. Configure the bank and vaults
3. Add cron job to /etc/crontab which at a minimum runs

usr/local/sbin/dirvish-expire --quiet ; /usr/local/sbin/dirvish-runall --quiet