memcached (ephemeral bucket) crashes during rebalance from 9 to 10 nodes

[ns_server:error,2017-05-20T21:21:13.367-07:00,ns_1@172.23.96.100:<0.15484.7>:ns_single_vbucket_mover:spawn_and_wait:110]Got unexpected exit signal {'EXIT',<0.10921.7>,

                            {unexpected_exit,

                             {'EXIT',<0.13145.7>,

                              {{{{badmatch,{error,closed}},

                                 [{mc_client_binary,cmd_vocal_recv,5,

                                   [{file,"src/mc_client_binary.erl"},

                                    {line,149}]},

                                  {mc_client_binary,select_bucket,2,

                                   [{file,"src/mc_client_binary.erl"},

                                    {line,336}]},

                                  {ns_memcached,ensure_bucket,2,

                                   [{file,"src/ns_memcached.erl"},

                                    {line,1225}]},

                                  {ns_memcached,handle_info,2,

                                   [{file,"src/ns_memcached.erl"},{line,718}]},

                                  {gen_server,handle_msg,5,

                                   [{file,"gen_server.erl"},{line,604}]},

                                  {ns_memcached,init,1,

                                   [{file,"src/ns_memcached.erl"},{line,168}]},

                                  {gen_server,init_it,6,

                                   [{file,"gen_server.erl"},{line,304}]},

                                  {proc_lib,init_p_do_apply,3,

                                   [{file,"proc_lib.erl"},{line,239}]}]},

                                {gen_server,call,

                                 ['ns_memcached-bucket-1',

                                  {get_dcp_docs_estimate,1009,

                                   "replication:ns_1@172.23.96.108->ns_1@172.23.96.107:bucket-1"},

                                  180000]}},

                               {gen_server,call,

                                [{'janitor_agent-bucket-1',

                                  'ns_1@172.23.96.108'},

                                 {if_rebalance,<0.10921.7>,

                                  {wait_dcp_data_move,

                                   ['ns_1@172.23.96.109','ns_1@172.23.96.107'],

                                   1009}},

                                 infinity]}}}}}

2017-05-20T21:21:02.235021-07:00 WARNING Breakpad caught crash in memcached version 5.0.0-2915. Writing crash dump to /opt/couchbase/var/lib/couchbase/crash/3944930a-f59f-3b3e-6feae241-7e37425b.dmp before terminating.

2017-05-20T21:21:02.235660-07:00 WARNING Stack backtrace of crashed thread:

2017-05-20T21:21:02.238630-07:00 WARNING     /opt/couchbase/bin/memcached() [0x4348f5]

2017-05-20T21:21:02.238688-07:00 WARNING     /opt/couchbase/bin/memcached(_ZN15google_breakpad16ExceptionHandler12GenerateDumpEPNS0_12CrashContextE+0x3d4) [0x486564]

2017-05-20T21:21:02.238717-07:00 WARNING     /opt/couchbase/bin/memcached(_ZN15google_breakpad16ExceptionHandler13SignalHandlerEiP9siginfo_tPv+0x97) [0x486877]

2017-05-20T21:21:02.238752-07:00 WARNING     /lib64/libpthread.so.0() [0x7f0b081b6100]

2017-05-20T21:21:02.238842-07:00 WARNING     /lib64/libc.so.6(gsignal+0x37) [0x7f0b062945f7]

2017-05-20T21:21:02.238903-07:00 WARNING     /lib64/libc.so.6(abort+0x148) [0x7f0b06295ce8]

2017-05-20T21:21:02.238984-07:00 WARNING     /lib64/libstdc++.so.6(_ZN9__gnu_cxx27__verbose_terminate_handlerEv+0x165) [0x7f0b06b999d5]

2017-05-20T21:21:02.239013-07:00 WARNING     /opt/couchbase/bin/memcached() [0x435b6c]

2017-05-20T21:21:02.239080-07:00 WARNING     /lib64/libstdc++.so.6() [0x7f0b06b97946]

2017-05-20T21:21:02.239146-07:00 WARNING     /lib64/libstdc++.so.6() [0x7f0b06b97973]

2017-05-20T21:21:02.239208-07:00 WARNING     /lib64/libstdc++.so.6() [0x7f0b06b97b93]

2017-05-20T21:21:02.239239-07:00 WARNING     /opt/couchbase/bin/../lib/../lib/ep.so() [0x7f0b01d1a473]

2017-05-20T21:21:02.239263-07:00 WARNING     /opt/couchbase/bin/../lib/../lib/ep.so() [0x7f0b01d1cacd]

2017-05-20T21:21:02.239288-07:00 WARNING     /opt/couchbase/bin/../lib/../lib/ep.so() [0x7f0b01c8d2e6]

2017-05-20T21:21:02.239309-07:00 WARNING     /opt/couchbase/bin/../lib/../lib/ep.so() [0x7f0b01c8d590]

2017-05-20T21:21:02.239330-07:00 WARNING     /opt/couchbase/bin/../lib/../lib/ep.so() [0x7f0b01c8db58]

2017-05-20T21:21:02.239352-07:00 WARNING     /opt/couchbase/bin/../lib/../lib/ep.so() [0x7f0b01c888da]

2017-05-20T21:21:02.239372-07:00 WARNING     /opt/couchbase/bin/../lib/../lib/ep.so() [0x7f0b01c88c34]

2017-05-20T21:21:02.239396-07:00 WARNING     /opt/couchbase/bin/../lib/../lib/ep.so() [0x7f0b01ce9ba3]

2017-05-20T21:21:02.239419-07:00 WARNING     /opt/couchbase/bin/../lib/libplatform_so.so.0.1.0() [0x7f0b087eab5e]

2017-05-20T21:21:02.239448-07:00 WARNING     /lib64/libpthread.so.0() [0x7f0b081aedc5]

2017-05-20T21:21:02.239528-07:00 WARNING     /lib64/libc.so.6(clone+0x6d) [0x7f0b06355ced]