It appears always, right from the start  of the job.
lxc is installed on my dispatcher.

Job description
https://pastebin.com/5g15YrWy

DUT description:
https://pastebin.com/bTKdaM5i

I know dut description is not full, but I want do step by step, firstly run lxc on device.

Maybe you can give some advice about DUT desc. 
I'm using fastboot flash for few partitions after that fastboot reboot

flash_cmds_order - it is order of flashing partition
fastboot_sequence - what is it?

Do you have some manual about this parameters description, cause have not found it on your website.

And one more question, lxc deployed on dispatcher, right?

Best regards,
Ilya Fedusiv