It would be very nice if people building distributions which make use of package managers could upgrade their devices between distribution revisions which cross YP release boundaries, i.e. upgrading from a Jethro based distro to a Krogoth based distro. To help ensure that this is possible we need to design automated QA tests which validate the upgrade path for each package manager we support. There are likely to be several challenges here, not least of all that we'll need to maintain a baseline state which the upgrade is tested from (previous state and previous release being the two obvious ones). I've added #9675 to the "Depends on" because we shouldn't invest too much time in this until a decision has been made on the future of SmartPM, etc.
Looks like a good thing to do, this would also be a documentation change, to list instructions for making the upgrade. Update from previous revision and state (like you mentioned Joshua) would make a viable scope for testing.
I'm moving this to M4 at it depends on 9675 which is targeted for 2.3 M4
I have created 14 testcases held withing the following testplan https://bugzilla.yoctoproject.org/tr_show_plan.cgi?plan_id=207
Test cases were executed on 2.4 cycle