We first saw this failure in zesty-proposed for armhf:
Check that device-mapper is available in the kernel.
Incompatible libdevmapper 1.02.136 (2016-11-05) and kernel driver (unknown version).
device mapper prerequisites not met
/dev/mapper/control: mknod failed: Operation not permitted
Failure to communicate with kernel device-mapper driver.
Check that device-mapper is available in the kernel.
Incompatible libdevmapper 1.02.136 (2016-11-05) and kernel driver (unknown version).
device mapper prerequisites not met
This test was added back in 0.9 and it's been passing on all architectures since then, but started failing in 0.13. At first we thought it was due to a recent change in the armhf architecture, but now I think it's because of a recent-ish change in lxc or the autopkgtest images used for armhf. The reason it only shows up on that architecture is that only the armhf architecture uses lxc containers for its autopkgtests.
It turns out this is reproducible in an amd64 container now too, although the autopkgtest infrastructure doesn't use it.
I'm not yet sure whether it's a missing dependency or some other change in the images, but we can at least rule out armhf specific problems.
https:/