Without further logs it's hard to say whether this really is a duplicate of the by-id path; but I highly suspect that MAAS deploying virtual machines with type virtio disks is not creating the VM disks with serial attributes; and this prevented curtin from successfully installing.
Without further logs it's hard to say whether this really is a duplicate of the by-id path; but I highly suspect that MAAS deploying virtual machines with type virtio disks is not creating the VM disks with serial attributes; and this prevented curtin from successfully installing.