2018-05-09 12:13:31,380: gnt-node add pid=1759 client:142 DEBUG Starting request <ganeti.http.client.HttpClientRequest 10.192.0.38:1811 POST /version at 0x7ff01c8cbe90>
2018-05-09 12:13:31,443: gnt-node add pid=1759 client:228 DEBUG Request <ganeti.http.client.HttpClientRequest 10.192.0.38:1811 POST /version at 0x7ff01c8cbe90> finished, errmsg=None
2018-05-09 12:13:32,893: gnt-node add pid=1759 cli:1225 ERROR Error during command processing
Traceback (most recent call last):
  File "/usr/share/ganeti/2.15/ganeti/cli.py", line 1221, in GenericMain
    result = func(options, args)
  File "/usr/share/ganeti/2.15/ganeti/rpc/node.py", line 141, in wrapper
    return fn(*args, **kwargs)
  File "/usr/share/ganeti/2.15/ganeti/client/gnt_node.py", line 351, in AddNode
    SubmitOpCode(op, opts=opts)
  File "/usr/share/ganeti/2.15/ganeti/cli.py", line 976, in SubmitOpCode
    reporter=reporter)
  File "/usr/share/ganeti/2.15/ganeti/cli.py", line 955, in PollJob
    return GenericPollJob(job_id, _LuxiJobPollCb(cl), reporter)
  File "/usr/share/ganeti/2.15/ganeti/cli.py", line 777, in GenericPollJob
    errors.MaybeRaise(msg)
  File "/usr/share/ganeti/2.15/ganeti/errors.py", line 531, in MaybeRaise
    raise errcls(*args)
OpExecError: need more than 1 value to unpack
Failure: command execution error:
need more than 1 value to unpack

ganeti                        2.15.2-7+deb9u1~bpo

and 

ganeti                        2.15.2-7+deb9u1