Overcloud introspection step fails with nodes in "clean failed" state

[cfarquhar]

Overcloud introspection fails:

(undercloud) [stack@director ~]$ openstack overcloud node introspect --provide abbca61f-63f5-4233-9dad-f4106e7993a5
Waiting for introspection to finish...
Started Mistral Workflow tripleo.baremetal.v1.introspect. Execution ID: f9551d40-8de8-4d6b-8a81-753d2c421742
Waiting for messages on queue 'tripleo' with no timeout.
Introspection of node abbca61f-63f5-4233-9dad-f4106e7993a5 completed. Status:SUCCESS. Errors:None
Successfully introspected 1 node(s).
Started Mistral Workflow tripleo.baremetal.v1.provide. Execution ID: 629938ae-3309-41e4-9eae-ee6618082b8e
Waiting for messages on queue 'tripleo' with no timeout.
[{u'result': u'Node abbca61f-63f5-4233-9dad-f4106e7993a5 did not reach state "available", the state is "clean failed", error: Failed to prepare node abbca61f-63f5-4233-9dad-f4106e7993a5 for cleaning: IPMI call failed: chassis bootdev pxe.'}]
Failed to set nodes to available state: Node abbca61f-63f5-4233-9dad-f4106e7993a5 did not reach state "available", the state is "clean failed", error: Failed to prepare node abbca61f-63f5-4233-9dad-f4106e7993a5 for cleaning: IPMI call failed: chassis bootdev pxe.

which is caused by the following ipmitool failure:

[stack@director ~]$ ipmitool -v -I lanplus -U root -P secrete -H 192.168.24.254 -p 624 chassis bootdev pxe
Set Chassis Boot Parameter 5 failed: Unspecified error

Downgrading virtualbmc from 2.0.0 to 1.6.0 works around the failure.