mariadb error 2006 "server has gone away" log

err.log

141023 14:47:57 [ERROR] mysqld got signal 11 ;
This could be because you hit a bug. It is also possible that this binary
or one of the libraries it was linked against is corrupt, improperly built,
or misconfigured. This error can also be caused by malfunctioning hardware.

To report this bug, see http://kb.askmonty.org/en/reporting-bugs

We will try our best to scrape up some info that will hopefully help
diagnose the problem, but since we have already crashed, 
something is definitely wrong and this may fail.

Server version: 10.0.14-MariaDB
key_buffer_size=134217728
read_buffer_size=131072
max_used_connections=2
max_threads=153
thread_count=2
It is possible that mysqld could use up to 
key_buffer_size + (read_buffer_size + sort_buffer_size)*max_threads = 467142 K  bytes of memory
Hope that's ok; if not, decrease some variables in the equation.

Thread pointer: 0x0x7fbcca845808
Attempting backtrace. You can use the following information to find out
where mysqld died. If you see no messages after this, something went
terribly wrong...
stack_bottom = 0x122c50e90 thread_stack 0x48000
0   mysqld                              0x00000001063a7d9d my_print_stacktrace + 60
0   mysqld                              0x0000000105e9191d handle_fatal_signal + 602
0   libsystem_platform.dylib            0x00007fff9415f5aa _sigtramp + 26
0   ???                                 0x000000010733da00 0x0 + 4415805952
0   mysqld                              0x000000010625e359 _ZNSt3__16__treeIP14dict_foreign_t20dict_foreign_compareNS_9allocatorIS2_EEE12__find_equalIS2_EER$
NS_16__tree_node_baseIPvEESC_RKT_ + 53
0   mysqld                              0x000000010625e2db _ZNSt3__16__treeIP14dict_foreign_t20dict_foreign_compareNS_9allocatorIS2_EEE15__insert_uniqueERKS$
_ + 33
0   mysqld                              0x000000010625e55d _ZNK36dict_foreign_add_to_referenced_tableclEP14dict_foreign_t + 37
0   mysqld                              0x0000000106259515 _Z31dict_create_foreign_constraintsP5trx_tPKcmS2_m + 4599
0   mysqld                              0x0000000106337d7c _Z33row_table_add_foreign_constraintsP5trx_tPKcmS2_m + 97
0   mysqld                              0x00000001062b06eb _ZN11ha_innobase6createEPKcP5TABLEP14HA_CREATE_INFO + 2915
0   mysqld                              0x0000000105e97ac6 _ZN7handler9ha_createEPKcP5TABLEP14HA_CREATE_INFO + 136
0   mysqld                              0x0000000105e9858d _Z15ha_create_tableP3THDPKcS2_S2_P14HA_CREATE_INFOP34st_mysql_const_unsigned_lex_string + 548
0   mysqld                              0x00000001060724b0 _Z17mysql_alter_tableP3THDPcS1_P14HA_CREATE_INFOP10TABLE_LISTP10Alter_infojP8st_orderb + 15119
0   mysqld                              0x00000001060bba93 _ZN19Sql_cmd_alter_table7executeEP3THD + 789
0   mysqld                              0x0000000105ff2979 _Z21mysql_execute_commandP3THD + 1109
0   mysqld                              0x0000000105ff1b25 _Z11mysql_parseP3THDPcjP12Parser_state + 516
0   mysqld                              0x0000000105fef3a7 _Z16dispatch_command19enum_server_commandP3THDPcj + 1003
0   mysqld                              0x0000000105ff167c _Z10do_commandP3THD + 231
0   mysqld                              0x00000001060b7911 _Z24do_handle_one_connectionP3THD + 383
0   mysqld                              0x00000001060b7785 handle_one_connection + 59
0   libsystem_pthread.dylib             0x00007fff8e035899 _pthread_body + 138
0   libsystem_pthread.dylib             0x00007fff8e03572a _pthread_struct_init + 0
0   libsystem_pthread.dylib             0x00007fff8e039fc9 thread_start + 13

Trying to get some variables.
Some pointers may be invalid and cause the dump to abort.
Query (0x7fbcca83d820): is an invalid pointer
Connection ID (thread ID): 3
Status: NOT_KILLED

Optimizer switch: index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,engine_conditio
n_pushdown=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=on,loosescan=on,materialization=on,in_to_exists=on,semijoin=on,pa
rtial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=off,mrr_cost_based=off,mrr_sort_keys=off,outer_join_with_cache=on,semijoin_with_
cache=on,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=off,table_elimination=on,extended_keys=on,exists_to_in=on

The manual page at http://dev.mysql.com/doc/mysql/en/crashing.html contains
information that should help you find out what is causing the crash.