sql/mysqld.cc:873: void remove_global_thread(THD*): Assertion `1 == num_erased' failed | abort in remove_global_thread (sig=6)

Thread 28 (LWP 15107):
+bt
#0 0x000000340cc0c69c in pthread_kill () from /lib64/libpthread.so.0
#1 0x00000000006f08cd in handle_fatal_signal (sig=6) at /bzr/5.6-QA_val/Percona-Server-5.6.12-rc60.4/sql/signal_handler.cc:251
#2 <signal handler called>
#3 0x000000340c4328a5 in raise () from /lib64/libc.so.6
#4 0x000000340c434085 in abort () from /lib64/libc.so.6
#5 0x000000340c42ba1e in __assert_fail_base () from /lib64/libc.so.6
#6 0x000000340c42bae0 in __assert_fail () from /lib64/libc.so.6
#7 0x00000000006303de in remove_global_thread (thd=0x246efbf0) at /bzr/5.6-QA_val/Percona-Server-5.6.12-rc60.4/sql/mysqld.cc:873
#8 0x0000000000767eba in Delayed_insert::~Delayed_insert (this=0x246efbd0, __in_chrg=<optimized out>) at /bzr/5.6-QA_val/Percona-Server-5.6.12-rc60.4/sql/sql_insert.cc:2263
#9 0x0000000000767f81 in Delayed_insert::~Delayed_insert (this=0x246efbd0, __in_chrg=<optimized out>) at /bzr/5.6-QA_val/Percona-Server-5.6.12-rc60.4/sql/sql_insert.cc:2268
#10 0x00000000007636b6 in delayed_get_table (thd=0x22721370, grl_protection_request=<optimized out>, table_list=0x217af9a0) at /bzr/5.6-QA_val/Percona-Server-5.6.12-rc60.4/sql/sql_insert.cc:2437
#11 0x0000000000763d1b in open_and_lock_for_insert_delayed (thd=0x22721370, table_list=0x217af9a0) at /bzr/5.6-QA_val/Percona-Server-5.6.12-rc60.4/sql/sql_insert.cc:564
#12 0x00000000007654c5 in mysql_insert (thd=0x22721370, table_list=0x217af9a0, fields=..., values_list=..., update_fields=..., update_values=..., duplic=DUP_ERROR, ignore=false) at /bzr/5.6-QA_val/Percona-Server-5.6.12-rc60.4/sql/sql_insert.cc:732
#13 0x000000000077d2f7 in mysql_execute_command (thd=0x22721370) at /bzr/5.6-QA_val/Percona-Server-5.6.12-rc60.4/sql/sql_parse.cc:3647
#14 0x000000000077fc78 in mysql_parse (thd=0x22721370, rawbuf=0x22721378 "@$B\001", length=<optimized out>, parser_state=<optimized out>) at /bzr/5.6-QA_val/Percona-Server-5.6.12-rc60.4/sql/sql_parse.cc:6477
#15 0x00000000007807bd in dispatch_command (command=<optimized out>, thd=0x22721370, packet=0x23f5b9e0 "p\023r\"", packet_length=<optimized out>) at /bzr/5.6-QA_val/Percona-Server-5.6.12-rc60.4/sql/sql_parse.cc:1355
#16 0x00000000007814f5 in do_command (thd=0x22721370) at /bzr/5.6-QA_val/Percona-Server-5.6.12-rc60.4/sql/sql_parse.cc:1049
#17 0x000000000081f2bf in threadpool_process_request (thd=0x22721370) at /bzr/5.6-QA_val/Percona-Server-5.6.12-rc60.4/sql/threadpool_common.cc:312
#18 0x0000000000821c10 in handle_event (connection=0x131ce7b0) at /bzr/5.6-QA_val/Percona-Server-5.6.12-rc60.4/sql/threadpool_unix.cc:1466
#19 0x0000000000821cd8 in worker_main (param=0x1576800 <all_groups+2560>) at /bzr/5.6-QA_val/Percona-Server-5.6.12-rc60.4/sql/threadpool_unix.cc:1519
#20 0x00000000009ea66a in pfs_spawn_thread (arg=0x19548720) at /bzr/5.6-QA_val/Percona-Server-5.6.12-rc60.4/storage/perfschema/pfs.cc:1858
#21 0x000000340cc07851 in start_thread () from /lib64/libpthread.so.0
#22 0x000000340c4e890d in clone () from /lib64/libc.so.6

mysqld: /bzr/5.6-QA_val/Percona-Server-5.6.12-rc60.4/sql/mysqld.cc:873: void remove_global_thread(THD*): Assertion `1 == num_erased' failed.
10:40:35 UTC - mysqld got signal 6 ;
[...]
2013-08-13T20:40:35 [15089] Query: DELETE FROM `table20_int_autoinc` WHERE `col_char_10` = 'j' ORDER BY `col_bigint`,`col_bigint_default_null`,`col_bigint_key`,`col_bigint_key_default_null`,`col_bigint_not_null`,`col_bigint_not_null_key`,`col_char_10`,`col_char_10_default_null`,`col_char_10_key`,`col_char_10_key_default_null`,`col_char_10_not_null`,`col_char_10_not_null_key`,`col_char_255`,`col_char_255_default_null`,`col_char_255_key`,`col_char_255_key_default_null`,`col_char_255_not_null`,`col_char_255_not_null_key`,`col_enum`,`col_enum_default_null`,`col_enum_key`,`col_enum_key_default_null`,`col_enum_not_null`,`col_enum_not_null_key`,`col_int`,`col_int_default_null`,`col_int_key`,`col_int_key_default_null`,`col_int_not_null`,`col_int_not_null_key`,`pk` LIMIT 1 /*Generated by THREAD_ID 48*/