Comment 0 for bug 1060404

If grub is installed in a container (as happens, for instance, with the ubuntu-cloud template) then an update of grub or linux-image will cause update-grub to be run. It tries, finds it can't access the root device, fails, and causes the update to fail.

It would be better for update-grub to detect that it is in a container and simply exit 0, so that the apt-get can succeed. I'm attaching a debdiff which does that.