Mysterious acts of 3.1

Anyone able to say what this means?

Found while testing 3.1-BZR rev 9483

Program received signal SIGABRT, Aborted.
[Switching to Thread 0xb7541b90 (LWP 29220)]
0xb7fce410 in __kernel_vsyscall ()
#0 0xb7fce410 in __kernel_vsyscall ()
#1 0xb7b73085 in raise () from /lib/tls/i686/cmov/libc.so.6
#2 0xb7b74a01 in abort () from /lib/tls/i686/cmov/libc.so.6

#3 0x080f2cd5 in Debug::xassert (msg=0x82210f8 "CurrentDebug",
file=0x82210a4 "../../SQUID_3_1/src/debug.cc", line=709)
     at ../../SQUID_3_1/src/debug.cc:745

#4 0x080f3215 in Debug::getDebugOut () at ../../SQUID_3_1/src/debug.cc:709

#5 0x0810e0fc in fd_open (fd=20, type=4, desc=0x823e144 "async-io
completetion event: main") at ../../SQUID_3_1/src/fd.cc:187

#6 0x081b2ab5 in CommIO::Initialise () at ../../SQUID_3_1/src/comm.cc:2302
#7 0x0820570f in squidaio_thread_loop (ptr=0x874ac84) at
../../SQUID_3_1/src/CommIO.h:30
#8 0xb7fa64fb in start_thread () from /lib/tls/i686/cmov/libpthread.so.0
#9 0xb7c1ee5e in clone () from /lib/tls/i686/cmov/libc.so.6
Received on Mon Apr 06 2009 - 12:19:19 MDT