mariadb with oq_graph server crash when running query from 2+ connections

root@duduta:/home/unics# mysqld --debug

140616 11:47:26 [Warning] 'debug' is disabled in this build

140616 11:47:26 [Note] InnoDB: Using mutexes to ref count buffer pool pages

140616 11:47:26 [Note] InnoDB: The InnoDB memory heap is disabled

140616 11:47:26 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins

140616 11:47:26 [Note] InnoDB: Compressed tables use zlib 1.2.7

140616 11:47:26 [Note] InnoDB: Using Linux native AIO

140616 11:47:26 [Note] InnoDB: Using CPU crc32 instructions

140616 11:47:26 [Note] InnoDB: Initializing buffer pool, size = 256.0M

140616 11:47:26 [Note] InnoDB: Completed initialization of buffer pool

140616 11:47:26 [Note] InnoDB: Highest supported file format is Barracuda.

140616 11:47:26 [Note] InnoDB: 128 rollback segment(s) are active.

140616 11:47:26 [Note] InnoDB: Waiting for purge to start

140616 11:47:26 [Note] InnoDB:  Percona XtraDB (http://www.percona.com) 5.6.17-65.0 started; log sequence number 1411674093

140616 11:47:26 [Note] Plugin 'FEEDBACK' is disabled.

140616 11:47:26 [Note] Server socket created on IP: '127.0.0.1'.

140616 11:47:26 [Note] Event Scheduler: Loaded 0 events

140616 11:47:26 [Note] Reading of all Master_info entries succeded

140616 11:47:26 [Note] Added new Master_info '' to hash table

140616 11:47:26 [Note] mysqld: ready for connections.

Version: '10.0.12-MariaDB-1~wheezy-log'  socket: '/var/run/mysqld/mysqld.sock'  port: 3306  mariadb.org binary distribution

2014-06-16 11:47:47 7f40838e2700  InnoDB: Assertion failure in thread 139915061765888 in file ha_innodb.cc line 9254

InnoDB: Failing assertion: prebuilt->trx == thd_to_trx(ha_thd())

InnoDB: We intentionally generate a memory trap.

InnoDB: Submit a detailed bug report to http://bugs.mysql.com.

InnoDB: If you get repeated assertion failures or crashes, even

InnoDB: immediately after the mysqld startup, there may be

InnoDB: corruption in the InnoDB tablespace. Please refer to

InnoDB: http://dev.mysql.com/doc/refman/5.6/en/forcing-innodb-recovery.html

InnoDB: about forcing recovery.

140616 11:47:47 [ERROR] mysqld got signal 6 ;

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: 10.0.12-MariaDB-1~wheezy-log

key_buffer_size=134217728

read_buffer_size=2097152

max_used_connections=2

max_threads=102

thread_count=2

It is possible that mysqld could use up to 

key_buffer_size + (read_buffer_size + sort_buffer_size)*max_threads = 759849 K  bytes of memory

Hope that's ok; if not, decrease some variables in the equation.

Thread pointer: 0x0x7f4060993008

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 = 0x7f40838e1df0 thread_stack 0x48000

addr2line: 'mysqld': No such file

mysqld(my_print_stacktrace+0x2b)[0x7f40844736cb]

mysqld(handle_fatal_signal+0x422)[0x7f4084006482]

/lib/x86_64-linux-gnu/libpthread.so.0(+0xf030)[0x7f408365a030]

/lib/x86_64-linux-gnu/libc.so.6(gsignal+0x35)[0x7f4081cb5475]

/lib/x86_64-linux-gnu/libc.so.6(abort+0x180)[0x7f4081cb86f0]

mysqld(+0x710e89)[0x7f4084199e89]

/usr/lib/mysql/plugin/ha_oqgraph.so(_ZNK8oqgraph36cursor15record_positionEv+0x36)[0x7f407f9d7e36]

/usr/lib/mysql/plugin/ha_oqgraph.so(_ZNK8oqgraph310cursor_ptrneERKS0_+0x1b)[0x7f407f9d7ecb]

/usr/lib/mysql/plugin/ha_oqgraph.so(_ZN5boost19breadth_first_visitIN8oqgraph35graphENS_5queueIySt5dequeIySaIyEEEENS_11bfs_visitorISt4pairINS_20predecessor_recorderINS_24associative_property_mapINS_9unordered13unordered_mapIyyNS_4hashIyEESt8equal_toIyESaIS9_IKyyEEEEEENS_12on_tree_edgeEEEN10open_query12oqgraph_goalILb0ENS_18on_discover_vertexESM_EEEEENS_16two_bit_judy_mapINS1_25vertex_index_property_mapEEEEEvRKT_NS_12graph_traitsISY_E17vertex_descriptorERT0_T1_T2_+0x3e4)[0x7f407f9d2d74]

/usr/lib/mysql/plugin/ha_oqgraph.so(_ZN10open_query7oqgraph6searchEPiPyS2_+0xcde)[0x7f407f9cd33e]

/usr/lib/mysql/plugin/ha_oqgraph.so(_ZN10ha_oqgraph14index_read_idxEPhjPKhj16ha_rkey_function+0x36b)[0x7f407f9ca36b]

mysqld(_ZN7handler17ha_index_read_mapEPhPKhm16ha_rkey_function+0x14c)[0x7f408400aebc]

mysqld(+0x447fd3)[0x7f4083ed0fd3]

mysqld(_Z10sub_selectP4JOINP13st_join_tableb+0x161)[0x7f4083ecdf11]

mysqld(+0x45c55d)[0x7f4083ee555d]

mysqld(_ZN4JOIN10exec_innerEv+0xa46)[0x7f4083ef87a6]

mysqld(_ZN4JOIN4execEv+0x11)[0x7f4083efa581]

mysqld(_Z12mysql_selectP3THDPPP4ItemP10TABLE_LISTjR4ListIS1_ES2_jP8st_orderSB_S2_SB_yP13select_resultP18st_select_lex_unitP13st_select_lex+0x1dd)[0x7f4083ef71ed]

mysqld(_Z13handle_selectP3THDP3LEXP13select_resultm+0x28d)[0x7f4083efa8dd]

mysqld(+0x417561)[0x7f4083ea0561]

mysqld(_Z21mysql_execute_commandP3THD+0x4ba9)[0x7f4083eaabd9]

mysqld(+0x42379a)[0x7f4083eac79a]

mysqld(_Z16dispatch_command19enum_server_commandP3THDPcj+0x14df)[0x7f4083eadd5f]

mysqld(_Z24do_handle_one_connectionP3THD+0x47b)[0x7f4083f718fb]

mysqld(handle_one_connection+0x47)[0x7f4083f719d7]

/lib/x86_64-linux-gnu/libpthread.so.0(+0x6b50)[0x7f4083651b50]

/lib/x86_64-linux-gnu/libc.so.6(clone+0x6d)[0x7f4081d5f0ed]

Trying to get some variables.

Some pointers may be invalid and cause the dump to abort.

Query (0x7f404bc1f020): is an invalid pointer

Connection ID (thread ID): 4

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_condition_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,partial_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.