Rebalance failed with "Compactor for vbucket `src_bucket/173` (pid [{type,vbucket}"

./testrunner -i /tmp/testexec.4317.ini -p get-cbcollect-info=True,GROUP=bucket_op -t eventing.eventing_rebalance.EventingRebalance.test_eventing_rebalance_in_when_existing_eventing_node_is_processing_mutations,nodes_init=4,services_init=kv-eventing-index-n1ql,dataset=default,groups=simple,reset_services=True,doc-per-day=20,sock_batch_size=8,worker_count=8,cpp_worker_thread_count=8,GROUP=bucket_op

[2018-08-26 09:05:43,785] - [rest_client:1598] ERROR - {u'status': u'none', u'errorMessage': u'Rebalance failed. See logs for detailed reason. You can try again.'} - rebalance failed

[2018-08-26 09:05:43,915] - [rest_client:3134] INFO - Latest logs from UI on 172.23.107.146:

[2018-08-26 09:05:43,915] - [rest_client:3135] ERROR - {u'node': u'ns_1@172.23.107.146', u'code': 0, u'text': u'Compactor for vbucket `src_bucket/173` (pid [{type,vbucket},\n                                             {name,<<"src_bucket/173">>},\n                                             {important,false},\n                                             {fa,\n                                              {#Fun<compaction_new_daemon.13.106246998>,\n                                               [<<"src_bucket">>,\n                                                {173,<<"src_bucket/173">>},\n                                                {config,\n                                                 {30,undefined},\n                                                 {30,undefined},\n                                                 undefined,false,false,\n                                                 {daemon_config,30,131072,\n                                                  20971520}},\n                                                false,\n                                                {1535040278,0,false}]}}]) terminated unexpectedly (ignoring this): {noproc,\n                                                                                                                    {gen_server,\n                                                                                                                     call,\n                                                                                                                     [disksup,\n                                                                                                                      get_disk_data,\n                                                                                                                      infinity]}}', u'shortText': u'message', u'serverTime': u'2018-08-26T09:05:22.358Z', u'module': u'compaction_new_daemon', u'tstamp': 1535299522358, u'type': u'warning'}