This script allows a system to bootstrap the package system and a set of
initial packages on first boot. To enable pkg(8) bootstrapping, add the
following to /etc/rc.conf:
pkg_bootstrap_enable="YES"
A list of packages to be installed at bootstrap time can be specified with:
pkg_bootstrap_list="sudo tmux git kyua"
The environment for the pkg(8) bootstrap commands can be influenced using
the pkg_bootstrap_env variable. This can be helpful for overriding
environment variables such as ABI or OSVERSION:
pkg_bootstrap_env="OSVERSION=1200056"