Comment 10 for bug 1652147

Timestamps are of no use since I did other modifications.

Ok, I think I now know what happened. I had proposed enabled in Trusty (in my case to have those act as canaries for updates). So I got those new versions of shim/shim-signed back then. And together with grub2 (or maybe kernel) this was somehow working in Trusty. Then those updates got removed from the archive but not replaced by newer versions. So the release-upgrade actually did *not* update those two packages. And now in the Xenial environment they actually break boot completely.

The problem I can see is that many people have proposed enabled at some point when they are asked to verify bugs. And IIRC the instructions do not tell them to turn off proposed after that. So this might happen to more people we think it could.

The work-around for me: disable secure boot in bios, boot, downgrade shim/shim-signed, reboot, enable secure boot in bios again.