Migratekit fails to detect root disk for multi-disk VMS

When migrating a vm with multiple disks migratekit fails during cutover becasue virt-v2v executed against non-os disk
resulting

Incremental copy 100% [===================================================================================================================================] (20/20 GiB, 15 PiB/s)
INFO[0029] Running virt-v2v-in-place
[ 0.0] Setting up the source: -i disk /dev/vdd
[ 1.1] Opening the source
[ 11.5] Checking filesystem integrity before conversion
[ 13.2] Detecting if this guest uses BIOS or UEFI to boot
[ 13.4] Inspecting the source
virt-v2v-in-place: error: inspection could not detect the source guest (or
physical machine) operating system.

Assuming that you are running virt-v2v/virt-p2v on a source which is
supported (and not, for example, a blank disk), then this should not
happen.

No root device found in this operating system image.

If reporting bugs, run virt-v2v-in-place with debugging enabled and include
the complete output:

virt-v2v-in-place -v -x [...]
Removing snapshot 100% [==============================================================================================================================================] (100/100) [0s:0s]
Error: exit status 1
Usage:
migratekit cutover [flags]

Flags:
--availability-zone string OpenStack availability zone for blockdevice & server
--flavor string OpenStack Flavor ID
-h, --help help for cutover
--network-mapping networkMapping Network mapping (e.g. 'mac=00:11:22:33:44:55,network-id=6bafb3d3-9d4d-4df1-86bb-bb7403403d24,subnet-id=47ed1da7-82d4-4e67-9bdd-5cb4993e06ff[,ip=1.2.3.4]')
--run-v2v Run virt2v-inplace on destination VM (default true)
--security-groups strings Openstack security groups, comma separated (e.g. '42c5a89e-4034-4f2a-adea-b33adc9614f4,6647122c-2d46-42f1-bb26-f38007730fdc')

Global Flags:
--compression-method compression-method Specifies the compression method to use for the disk (default skipz)
--debug Enable debug logging
--disk-bus-type disk-bus-type Specifies the type of disk controller to attach disk devices to. (default virtio)
--enable-qemu-guest-agent Sets the hw_qemu_guest_agent metadata parameter to yes
--os-type string Set os_type in the volume (image) metadata, (if set to "auto", it tries to detect the type from VMware GuestId)
--vmware-endpoint string VMware endpoint (hostname or IP only)
--vmware-password string VMware password
--vmware-path string VMware VM path (e.g. '/Datacenter/vm/VM')
--vmware-username string VMware username
--volume-type string Openstack volume type
--vz-unsafe-volume-by-name Only use the name to find a volume - workaround for virtuozzu - dangerous option

Start at the migratekit cutover entry point and trace how disks are selected before virt-v2v-in-place runs. Reproduce the multi-disk case from the reported output, then verify that the OS/root disk is selected and cutover no longer runs virt-v2v against a non-OS disk.