rebalance failure in build sanity - dcp_wait_for_data_move_failed error with mover_crashed

rebalance and failover tests in build sanity started failing with this error:

10:18:12 [2019-07-15 10:18:12,968] - [rest_client:3250] ERROR - {u'node': u'ns_1@172.23.107.160', u'code': 0, u'text': u'Rebalance exited with reason {mover_crashed,\n {unexpected_exit,\n {\'EXIT\',<0.14657.1>,\n dcp_wait_for_data_move_failed,"default",\n 1022,\'ns_1@172.23.107.160\',\n [\'ns_1@172.23.107.191\',\n \'ns_1@172.23.107.190\'],\n {error,no_stats_for_this_vbucket,\n [{ns_single_vbucket_mover,\n \'wait_dcp_data_move/5-fun-0\',5,\n [

{file,"src/ns_single_vbucket_mover.erl"}

,\n

{line,465}

]},\n {proc_lib,init_p,3,\n [

{file,"proc_lib.erl"}

,

{line,232}

]}]}}}}.\nRebalance Operation Id = 28925993fb4e1742245387a9d86c32d6', u'shortText': u'message', u'serverTime': u'2019-07-15T10:18:05.523Z', u'module': u'ns_orchestrator', u'tstamp': 1563211085523, u'type': u'critical'}
10:18:12 [2019-07-15 10:18:12,968] - [rest_client:3250] ERROR - {u'node': u'ns_1@172.23.107.160', u'code': 0, u'text': u'Worker <0.14569.1> (for action {move,{1022,\n [\'ns_1@172.23.107.160\',undefined],\n [\'ns_1@172.23.107.191\',\n \'ns_1@172.23.107.190\'],\n []}}) exited with reason {unexpected_exit,\n {\'EXIT\',\n <0.14657.1>,\n dcp_wait_for_data_move_failed,\n "default",\n 1022,\n \'ns_1@172.23.107.160\',\n [\'ns_1@172.23.107.191\',\n \'ns_1@172.23.107.190\'],\n {error,\n no_stats_for_this_vbucket,\n [{ns_single_vbucket_mover,\n \'wait_dcp_data_move/5-fun-0\',\n 5,\n [

{file,\n "src/ns_single_vbucket_mover.erl"}

,\n

{line,\n 465}

]},\n {proc_lib,\n init_p,3,\n [

{file,\n "proc_lib.erl"}

,\n

{line,\n 232}

]}]}}}', u'shortText': u'message', u'serverTime': u'2019-07-15T10:18:05.519Z', u'module': u'ns_vbucket_mover', u'tstamp': 1563211085519, u'type': u'critical'}
10:18:12 [2019-07-15 10:18:12,968] - [rest_client:3250] ERROR - {u'node': u'ns_1@172.23.107.160', u'code': 0,

last good build: 6.5.0-3761
logs attached