Backtrace... sort of (wasRe: pqReadData() -- backend closed the channel unexpectedly.)

I recompiled with debugging enabled, but it does not seem to have helped
much with this backtrace output. Any suggestions?

jc12# gdb -c postgres.core
GNU gdb 4.18
Copyright 1998 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB. Type "show warranty" for details.
This GDB was configured as "i386-unknown-freebsd".
Core was generated by `postgres'.
Program terminated with signal 4, Illegal instruction.
#0 0x812023a in ?? ()
(gdb) bt
#0 0x812023a in ?? ()
#1 0x81200fc in ?? ()
#2 0x811f97c in ?? ()
#3 0x813a4a8 in ?? ()
#4 0x811fae0 in ?? ()
#5 0x813ae0e in ?? ()
#6 0x80e730e in ?? ()
#7 0x80da636 in ?? ()
#8 0x80da523 in ?? ()
#9 0x80db434 in ?? ()
#10 0x80da1e1 in ?? ()
#11 0x80da19c in ?? ()
#12 0x80d9ffb in ?? ()
#13 0x80e12e4 in ?? ()
#14 0x80e11f3 in ?? ()
#15 0x80e20a4 in ?? ()
#16 0x80e1593 in ?? ()
#17 0x80e1449 in ?? ()
#18 0x80feec7 in ?? ()
#19 0x80ff0bd in ?? ()
#20 0x810018c in ?? ()
#21 0x80ea75a in ?? ()
#22 0x80ea2ce in ?? ()
#23 0x80e94d1 in ?? ()
---Type <return> to continue, or q <return> to quit---
#24 0x80e8ee7 in ?? ()
#25 0x80c9465 in ?? ()
#26 0x80645f5 in ?? ()
(gdb) q
jc12# exit
exit