Comment 1 for bug 1104463

1. Patching zz-update-grub is almost certainly the wrong answer, as manual runs of update-grub(1) or, indeed, anything else that might call it that we've not noticed yet, will show exactly the same issue.

2. Exiting update-grub 0 on containers seems like a sane workaround, but probably long-term silly. And workarounds often end up as long-term tech debt.

3. Fixing it somehow magically in grub-probe sounds appealing, until we realise that there'd be no way for grub-probe to tell update-grub "well, I looked, but couldn't find anything useful for you" without either exiting non-zero (which is exactly what it does right now) or returning completely bogus info for you to later write to you grub config (ewww).

Given the above, the second option seems the simplest and sanest for now, with an enormous FIXME comment on it, mentioning that lxc is meant to get device namespaces "some day", and when that happens, this can probably be revisited. Thoughts?