Comment 2 for bug 2013339

I don't know when you last tried it but likely after https://code.launchpad.net/~vorlon/launchpad-buildd/+git/launchpad-buildd/+merge/442776 got eventually landed and deployed on all builders and lots of other things were fixed in livecd-rootfs to use actually real /dev not a fake one, lots of stuff w.r.t. loop mounts got resolved.

And dm-crypt likely was fixed as a side-effect. Probably sometime in the last few weeks of mantic (see all the fighting in livecd-rootfs changelog uploads)