# Pastebin tLy2gQb7
$ sudo systemd-nspawn -i ubuntu.img -b
No GPT or MBR partition table discovered on
    /mnt/bigdisk/ubuntu/ubuntu.img
Note that the disk image needs to either contain only a single MBR partition of
type 0x83 that is marked bootable, or a single GPT partition of type 0FC63DAF-8483-4772-8E79-3D69D8477DE4 or follow
    http://www.freedesktop.org/wiki/Specifications/DiscoverablePartitionsSpec/
to be bootable with systemd-nspawn.