This is primarily aimed at failed updates due to package conflicts, and
affects treatment of failed updates. Whereas before potentially a large
number of packages would need to be synced for each attempt, they can now
be persisted. Requires rsync. There may be better ways to implement this,
e.g. using secondary cache path that is only used on followup attempts and
then wiped on success, which avoids polluting current cache.
Since all post-installkernel steps are assumed to operate in the updated
installation, it's necessary to chroot all of the followup steps in the new
boot environment. Set up and mount the source and object directories at the
same paths inside the BE root, and clean up to the extent changes were made.
This commit fixes upgrading using beinstall past the new ntpd user change.
Improve testability of changes to this script while I'm here.
Reported by: rpokala (earlier patch)
This is meant to install a new BE (boot environment) given a fully built
world/kernel. In addition to installing world and kernel in the new BE,
it also automatically performs /etc updates (using etcupdate or mergemaster)
and package updates (using pkg).
Because this process is performed in a new BE, it reduces the need for a
second reboot. It also means a reboot into a partially updated system (due
to install or hardware failure) can't happen.
Inspired by and similar in function to Solaris/illumos-style upgrades.
