My last time was an issue (or oversight) with pacman, which allowed me to update libicu-x.y without updating all its reverse dependencies. Some important part o

My last time was an issue (or oversight) with pacman, which allowed me to update libicu-x.y without updating all its reverse dependencies. Some important part of the system depended on libicu-x.z (earlier version) which was no longer present so I had to get to the rescue console. So this was an Arch-specific issue that could have been mitigated with ZFS snapshots. E.g. Gentoo does consistency checks of dynamic libs, and other systems don't allow you to make such upgrades. I had something critical happen to me twice in one year and both times it would have been avoidable with an earlier snapshot of the rootfs. I will definitely do that next time I re-format a disk.