mysqld: maria-5.5/mysys/lf_alloc-pin.c:220: _lf_pinbox_put_pins: Assertion `pins->pin[i] == 0' failed.
[ERROR] mysqld got signal 6 ;

#6  0x00007f912f074d4d in __GI___assert_fail (assertion=0xe7f086 "pins->pin[i] == 0", file=<optimized out>, line=220, function=<optimized out>) at assert.c:81
#7  0x0000000000cc6aff in _lf_pinbox_put_pins (pins=0x3af2280) at mysys/lf_alloc-pin.c:220
#8  0x000000000095b94d in lf_pinbox_put_pins (pins=0x3af2280) at include/lf.h:173
#9  0x000000000095ca10 in trnman_end_trn (trn=0x3b1c860, commit=1 '\001') at storage/maria/trnman.c:515
#10 0x000000000098fb17 in ma_commit (trn=0x3b1c860) at storage/maria/ma_commit.c:72
#11 0x000000000095867b in ha_maria::implicit_commit (thd=0x3b6ed20, new_trn=false) at storage/maria/ha_maria.cc:2824
#12 0x0000000000614484 in mysql_execute_command (thd=0x3b6ed20) at sql/sql_parse.cc:4518
#13 0x0000000000617299 in mysql_parse (thd=0x3b6ed20, rawbuf=0x3b7a868 "DELETE FROM `B` WHERE `pk` >= 0 LIMIT 2", length=39, parser_state=0x7f912629c550) at sql/sql_parse.cc:5736
#14 0x000000000060ab0f in dispatch_command (command=COM_QUERY, thd=0x3b6ed20, packet=0x3b72751 "DELETE FROM `B` WHERE `pk` >= 0 LIMIT 2", packet_length=39) at sql/sql_parse.cc:1055
#15 0x0000000000609dc6 in do_command (thd=0x3b6ed20) at sql/sql_parse.cc:794
#16 0x000000000070b6af in do_handle_one_connection (thd_arg=0x3b6ed20) at sql/sql_connect.cc:1253
#17 0x000000000070b09a in handle_one_connection (arg=0x3b6ed20) at sql/sql_connect.cc:1168
#18 0x00007f912fdb6efc in start_thread (arg=0x7f912629d700) at pthread_create.c:304

Trying to get some variables.
Some pointers may be invalid and cause the dump to abort.
Query (0x3b7a868): DELETE FROM `B` WHERE `pk` >= 0 LIMIT 2
Connection ID (thread ID): 9
Status: NOT_KILLED

maria/5.5
bzr version-info
revision-id: sergii@pisem.net-20120822213345-yhkfv11akr0di65o
date: 2012-08-22 23:33:45 +0200
build-date: 2012-08-24 04:17:42 +0400
revno: 3503

thread1:
        OPTIMIZE TABLE _table ;

thread2:
        OPTIMIZE TABLE _table ;

query:
        DELETE FROM _table WHERE `pk` >= _digit LIMIT 2 | 
        INSERT INTO _table ( `pk` ) VALUES (NULL);

perl ./runall.pl  --queries=100M --duration=600 --engine=Aria --grammar=1.yy  --basedir=<basedir>