Comment 10 for bug 1728760

It's not the demotion of the aufs-dkms relationship from depends to recommends that triggers this, but that the 17.04 aufs-tools had no dependency at all and 17.10 adds the recommends.

I think aufs-tools needs to drop this Recommends in SRU and until after 18.04 release, since all of our kernels logically satisfy the relationship and expressing it in apt does bad things to the upgrade.