installs a boot environment using the current
also automatically performs
package updates using
automatically in the new boot environment sandbox.
Upon successful completion, the system will be ready to boot into the new boot
Upon failure, the target boot environment will be destroyed.
In all cases, the running system is left untouched
and a reboot into a partially updated system
(due to install or hardware failure) cannot happen.
Additionally, the full installation process requires
only one reboot as it is performed
in a new boot environment.
requires a fully built world and kernel.
It also requires
which are not present in the base system and have to be installed manually.
are world and kernel flags like
as described in