Comment 9 for bug 1604421

I think testing flashing 40 + flashing newer without --bootstrap/--wipe was never done.

You can try using my (still working, flashed formerly and dist-upgraded) krillin's home directory:

https://private-fileshare.canonical.com/~tjyrinki/krillin/

Likewise I could extract pieces of / or other parts to try to pinpoint the difference.