RFC 697: Test (and enable) interrupted upgrades
Created by: efritz
See RFC 697: Multiple version upgrades.
I'm unsure what happens if an upgrade process is interrupted halfway through. It could be nothing, but we might have some odd issues with the version check at the beginning of the process.
If there is an issue with version state, one solution to a fuzzy state would be to add an upgrading
column to the versions
table so that this state can be read by frontends starting up ("whoops you didn't finish your upgrade!; exit 1") as well as the migrator service ("looks like we got interrupted, let's start from where we left off").