Martin was kind enough to send me some code below. Others are welcome 
to try on other platforms, just out of curiosity. How to fix/avoid is 
another matter.


At 11:44 PM -0800 2/4/02, Martin McClure wrote:
>You said you were interested in crash reports, so here's one. Though 
>this one is probably an expected crash, I was attempting to make 
>BlockContext uncompact, and I was doing it from code inside a 
>block...
>
>I started from a fresh 3.2g-4653 image and executed:
>
>Smalltalk compactClassesArray do:
>	[:each | (each notNil) & (each ~~ CompiledMethod) ifTrue:
>		[each becomeUncompact]].
>




Date/Time:  2002-02-05 16:03:36 -0800
OS Version: 10.1.2 (Build 5P48)
Host:       otter

Command:    Squeak VM Opt
PID:        5658

Exception:  EXC_BAD_ACCESS (0x0001)
Codes:      KERN_INVALID_ADDRESS (0x0001) at 0x27732070

Thread 0 Crashed:
  #0   0x00064754 in markAndTrace
  #1   0x00064774 in markAndTrace
  #2   0x000649f0 in markAndTraceInterpreterOops
  #3   0x00064af4 in markPhase
  #4   0x0005d054 in incrementalGC
  #5   0x0005dd64 in instantiateContextsizeInBytes
  #6   0x00066c08 in primitiveBlockCopy
  #7   0x00062b2c in interpret
  #8   0x000a092c in main
  #9   0x00003bf0 in _start
  #10  0x00003a20 in start

PPC Thread State:
   srr0: 0x00064754 srr1: 0x0000d030                vrsave: 0x00000000
    xer: 0x00000004   lr: 0x00064774  ctr: 0x70004970   mq: 0x00000000
     r0: 0x03f128f4   r1: 0xbffff9e0   r2: 0x03f11d78   r3: 0x00000040
     r4: 0x00000000   r5: 0x00000000   r6: 0x000d453c   r7: 0x000e4680
     r8: 0x000e0618   r9: 0x000ebe8c  r10: 0x00000002  r11: 0x04300940
    r12: 0x70004970  r13: 0x00000000  r14: 0x00000000  r15: 0x00000000
    r16: 0x00000000  r17: 0x00000000  r18: 0x00000000  r19: 0x00000000
    r20: 0x00000000  r21: 0x03f6130c  r22: 0x1f24e35f  r23: 0x00000001
    r24: 0x0d86e35f  r25: 0x000ebe80  r26: 0x000e86f8  r27: 0x000e0618
    r28: 0x000e4680  r29: 0xf369746a  r30: 0x27732070  r31: 0x0006453c

-- 
--
===========================================================================
John M. McIntosh <johnmci at smalltalkconsulting.com> 1-800-477-2659
Corporate Smalltalk Consulting Ltd.  http://www.smalltalkconsulting.com
===========================================================================