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.
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.

key_buffer_size=8388600
read_buffer_size=131072
max_used_connections=1
max_connections=100
threads_connected=1
It is possible that mysqld could use up to 
key_buffer_size + (read_buffer_size + sort_buffer_size)*max_connections = 225791 K
bytes of memory
Hope that's ok; if not, decrease some variables in the equation.

thd=0x85fb768
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...
Cannot determine thread, fp=0xbe7fe938, backtrace may not be correct.
Stack range sanity check OK, backtrace follows:
0x809116e handle_segfault + 414
0x8304272 pthread_sighandler + 162
0x806464c fix_length_and_dec__19Item_func_concat_ws + 252
0x8055b52 fix_fields__9Item_funcP3THDP13st_table_listPP4Item + 354
0x8384467 fix_fields__19Item_func_concat_wsP3THDP13st_table_listPP4Item + 87
0x80baf75 setup_fields__FP3THDPP4ItemP13st_table_listRt4List1Z4ItembPt4List1Z4ItemT4 + 101
0x80c0298 prepare__4JOINPPP4ItemP13st_table_listUiP4ItemUiP8st_orderT6T4T6P13st_select_lexP18st_select_lex_unit + 264
0x80c3288 mysql_select__FP3THDPPP4ItemP13st_table_listUiRt4List1Z4ItemP4ItemUiP8st_orderT7T5T7UlP13select_resultP18st_select_lex_unitP13s + 584
0x80c00dc handle_select__FP3THDP6st_lexP13select_result + 156
0x809f9b3 mysql_execute_command__FP3THD + 1315
0x80a4289 mysql_parse__FP3THDPcUi + 169
0x809e78d dispatch_command__F19enum_server_commandP3THDPcUi + 1389
0x809e214 do_command__FP3THD + 196
0x809da70 handle_one_connection + 768
0x83021ee pthread_start_thread + 158
0x833333a thread_start + 4
New value of fp=(nil) failed sanity check, terminating stack trace!
Please read http://www.mysql.com/doc/en/Using_stack_trace.html and follow instructions on how to resolve the stack trace. Resolved
stack trace is much more helpful in diagnosing the problem, so please do 
resolve it
Trying to get some variables.
Some pointers may be invalid and cause the dump to abort...
thd->query at 0x8602230 = select
  concat_ws('|',str,str)
from
  test1
thd->thread_id=1
The manual page at http://www.mysql.com/doc/en/Crashing.html contains
information that should help you find out what is causing the crash.

Number of processes running now: 0
040307 11:37:39  mysqld restarted
040307 11:37:39  InnoDB: Database was not shut down normally!
InnoDB: Starting crash recovery.
InnoDB: Reading tablespace information from the .ibd files...
InnoDB: Restoring possible half-written data pages from the doublewrite
InnoDB: buffer...
040307 11:37:39  InnoDB: Starting log scan based on checkpoint at
InnoDB: log sequence number 0 5221190.
InnoDB: Doing recovery: scanned up to log sequence number 0 5221190
040307 11:37:39  InnoDB: Flushing modified pages from the buffer pool...
040307 11:37:39  InnoDB: Started; log sequence number 0 5221190
/usr/local/mysql/libexec/mysqld: ready for connections.
Version: '4.1.2-alpha-nightly-20040229'  socket: '/tmp/mysql.sock'  port: 3306