Hi All,

� � I'm seeing an occasional crash in Cog when stepping the simulator when working on Spur. �The crash comes about when the system executes primitiveStoreStackp (primitive 76) as part of ContextPart>>push:, and a code compaction occurs within the primitive. �The crash.dmp file looks like the following (eliding for brevity):

Bus error Sat Sep 21 06:03:12 2013

...

C stack backtrace:

0 � Squeak � � � � � � � � � � � � � � �0x000700a1 reportStackState + 145

1 � Squeak � � � � � � � � � � � � � � �0x00070a32 sigsegv + 306

2 � libSystem.B.dylib � � � � � � � � � 0x99fa105b _sigtramp + 43

3 � ??? � � � � � � � � � � � � � � � � 0xffffffff 0x0 + 4294967295

4 � Squeak � � � � � � � � � � � � � � �0x00101d9a interpret + 2970

...

Smalltalk stack dump:

0xbffe2ae8 M MethodContext(ContextPart)>push: 0x1d95abac: a(n) MethodContext

0xbffe2b0c M MethodContext(ContextPart)>return:from: 0x1d95ab50: a(n) MethodContext

0xbffe2b34 I MethodContext(ContextPart)>methodReturnReceiver 0x1d95ab50: a(n) MethodContext

0xbffe2b5c M MethodContext(InstructionStream)>interpretNextInstructionFor: 0x1d95ab50: a(n) MethodContext

0xbffe2b78 M MethodContext(ContextPart)>step 0x1d95ab50: a(n) MethodContext

...

Most recent primitives

...

primitiveWait

at:put:

signal

basicNew

shallowCopy

findSubstring:in:startingAt:matchTable:

indexOfAscii:inString:startingAt:

perform:

objectAt:

at:

findNextUnwindContextUpTo:

at:put:

stackp:

**CompactCode**

But this isn't telling me enough.

Firstly I've just committed changes to�http://www.squeakvm.org/svn/squeak/branches/Cog/platforms/Mac%20OS/vm/sqMacMain.c and�http://www.squeakvm.org/svn/squeak/branches/Cog/platforms/unix/vm/sqUnixMain.c to also print the register state when the VM segfaults or gets sent SGUSR1 etc. �I can't test on FreeBSD. �If anyone builds with these changes on Free BSD can they please let me know if they work or not?

Secondly perhaps someone has a reproducible case coming from running e.g. ContextPart>>runAtEachStep: type code? �If so, please can I have a copy?

Lastly, if anyone has a crash that matches the above, but with the new crash dump info, I'd love to see the crash.dmp file.

Thanks,

Eliot