Re: [Swarm-Support] arborgamesII test fail on Fedora 5

[Paul Johnson]

Sunwoo Park wrote:
> Hi everyone, 
>
> I installed Swarm 2.2.3 on Fedora 5/Pentium 4 PC, and ran test examples
> included in swarmapps-objc-2.2-2. All examples except for arborgamesII
> worked fine. When I ran arborgames, I got following messages.
> << In Batch mode >>
> Nil receiver for step
> Arboted 
>
>   
Yes, it is due to new tightness in gcc checking for messages to nil.  
There is an easy fix.  Here's how I found the problem--run "gdb  
arborgames" and  type "run" and then, after it crashes,  type "bt".   It 
points at one line in Forest.m, where you see code applied to  "aTree".

#0  0x00415410 in __kernel_vsyscall ()
#1  0x007e5d40 in raise () from /lib/libc.so.6
#2  0x007e7591 in abort () from /lib/libc.so.6
#3  0x00e178e8 in nil_method (receiver=0x0, op=0x8052bb0)
   at /usr/src/debug/swarm-2.2.3/libobjc/nil_method.c:36
#4  0x08049f0f in -[Forest processYoungTrees] (self=0x922dbd0,
   _cmd=0x8052ab8) at Forest.m:426



Some cells are empty, and it is easy to see what you need to do.  
Revise code to check to see if aTree exists before doing anything to 
it.  I have the code in another computer at home, but I assure you it is 
easy to fix.  SOmething like changing this:

    treeStatus = [aTree step];

To

   if (aTree) treeStatus = [aTree step];

I'm finding more problems like that in the swarmapps-objc since the 
newest gcc came out.  Eventually I'll package all together in a fix tarball.

But I do think it is educational for users to learn to fix these things 
themselves.
pj



> << In graphic mode >>
> Color ForestGreen
> Color MediumSeaGreen
>  ...
> Color LemonChiffon
> Nil reciever for step
> aborted
>
> My old swarm code, which ran successfully under the previous version,
> also
> produced the same error messages. So, I would like to figure it out why.
> I would appreciate any help from you.
>
> FYI,
> I installed Swarm 2.3. with the following rpms.
> blt-2.4z-6FC5.i386.rpm
> blt-2.4z-6FC5.src.rpm
> blt-debuginfo-2.4z-6FC5.i386.rpm
> Jdk-1_5_0_06-linux-i586.rpm
> swarm-2.2.3-1_fc5.i386.rpm
> swarm-2.2.3-1_fc5.src.rpm
> swarm-debuginfo-2.2.3-1_fc5.i386.rpm
> swarm-gcjswarm-2.2.3-1_fc5.i386.rpm
> swarm-jdk-2.2.3-1_fc5.i386.rpm
> swarm-static-2.2.3-1_fc.i386.rpm
> hdf5-1.6.5-5.fc5
> gcc-4.1.1-1.fc5
>
> regards,
>
> Sunwoo
>
>
>
> _______________________________________________
> Support mailing list
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> http://www.swarm.org/mailman/listinfo/support
>   


--
Paul E. Johnson                       email: address@hidden
Dept. of Political Science            http://pj.freefaculty.org
1541 Lilac Lane, Rm 504                              
University of Kansas                  Office: (785) 864-9086
Lawrence, Kansas 66044-3177           FAX: (785) 864-5700