[Swarm-Support] Debugging Help

[Crile Doscher]

Hi all,
  Could someone point me in the right direction with some debugging?
I'm using Swarm2.2 (Obj C) on Fedora Core 5.  I'm stuck and would
appreciate any insights or thoughts on where to look.  Some (hopefully)
relevant points:
*Code uses MultiGrid2d objects to allow multiple agents in one cell.
For this version I have shifted some code around but haven't been able
to track down how those changes are significant to this error - previous
code ran fine.  
*Code compiles with no new warnings
*On execution, control widgets are drawn.  Once Start is pressed, a 2d
window (ZoomRaster) is drawn but two displays (Object2dDisplay) are not;
then the code crashes:

<...some output text deleted...>
Main.m: observerSwarm go! here (this is a comment inserted by me for
debugging)
*** event raised for error: InvalidArgument
*** function: -[Object(s) _doesNotRecognize:](),
file: 
/home/pauljohn/LinuxDownloads/redhat/BUILD/swarm-2.2.2/src/defobj/DefObject.m, 
line: 834
MultiGrid2d does not recognize begin:
*** execution terminating due to error
/home/pauljohn/LinuxDownloads/redhat/BUILD/swarm-2.2.2/src/defobj/Symbol.m:187 
-[Error(c) _raiseEvent:]
Aborted

*"MultiGrid2d does not recognize begin:" looks quite crucial but I can't
see where there's a call for MultiGrid2d to begin in the code
*Under gdb, here's the backtrace:

(gdb) bt
#0  0x4ba47402 in __kernel_vsyscall ()
#1  0x4ba8d069 in raise () from /lib/libc.so.6
#2  0x4ba8e671 in abort () from /lib/libc.so.6
#3  0x006b662e in debugabort () from /usr/lib/swarm/libswarm.so.0
#4  0x006861ee in _obj_initModule () from /usr/lib/swarm/libswarm.so.0
#5  0x00679896 in _obj_dropAlloc () from /usr/lib/swarm/libswarm.so.0
#6  0x0067b926 in getMethodFor () from /usr/lib/swarm/libswarm.so.0
#7  0x006c0893 in objc_msg_lookup () from /usr/lib/swarm/libswarm.so.0
#8  0x006c0ed3 in objc_msg_lookup () from /usr/lib/swarm/libswarm.so.0
#9  0x0066409c in get_number_of_arguments ()
from /usr/lib/swarm/libswarm.so.0
#10 0x00660434 in get_number_of_arguments ()
from /usr/lib/swarm/libswarm.so.0
#11 0x0066cb1e in _activity_context_error ()
from /usr/lib/swarm/libswarm.so.0
#12 0x0066c926 in _activity_context_error ()
from /usr/lib/swarm/libswarm.so.0
#13 0x0066c926 in _activity_context_error ()
from /usr/lib/swarm/libswarm.so.0
#14 0x0066c926 in _activity_context_error ()
from /usr/lib/swarm/libswarm.so.0
#15 0x0066c926 in _activity_context_error ()
from /usr/lib/swarm/libswarm.so.0
#16 0x0066c926 in _activity_context_error ()
from /usr/lib/swarm/libswarm.so.0
#17 0x0066cf72 in _activity_context_error ()
from /usr/lib/swarm/libswarm.so.0
#18 0x005f8ce1 in swarm_force_references ()
from /usr/lib/swarm/libswarm.so.0
#19 0x005f96fa in swarm_force_references ()
from /usr/lib/swarm/libswarm.so.0
#20 0x08049616 in main (argc=Cannot access memory at address 0xadb
) at main.m:36

*main.m:36 is [observerSwarm go];
*I'm not quite sure where things go after [observerSwarm go];.  Does
control shift to ModelSwarm?  

Thanks - 
Crile

Dr Crile Doscher
Natural Resources Engineering
Lincoln University
New Zealand