program does not crash when attached to gdbserver

[Dr. Rolf Jansen <rj@cyclaero.com>]

My setup is as follows:

gdb/gdbserver built from CVS trunk from today (6.8.50.20090612-cvs)

The source were configured and compiled unchanged:

gdb was configured as "--host=powerpc-apple-darwin9.7.0 --target=i386- 
mingw32msvc".
gdbserver was configured as "--host=i386-mingw32msvc --target=i386- 
mingw32msvc".

gdb has been compiled by gcc-4.2 on Mac OS X 10.5.7 with the Xcode  
3.1.2 toolchain
gdbserver has been compiled with a gcc-4.3.1 cross compiler (-- 
host=powerpc-apple-darwin9.7.0 --target=i386-mingw32msvc)

The situation is, that I am trying to debug a huge GUI application for  
Win32. It has been entirely compiled with said cross-compiler using  
the options -gdwarf-2, -O0. I can step through each part, so the  
symbols are there.

The problem is that the application crashes consistently after a  
certain sequence of user interactions if it runs by its own. However,  
the same binary does not crash, once it is attached to gdbserver, and  
it does not crash even when continuing  with a couple of stress tests  
beyound the point at which it would have crashed without gdbserver.

It would help so much to find the bug if the program would crash into  
gdb and if gdb could show me the related source code. This usually  
works quite well, for example when writing to memory at NULL.

Perhaps somebody has an idea about what type of bug might cause the  
behaviour described above.

There was a debugger for Mac OS Classic called MacsBug, that had a  
setting for scrambling the memory, so that accessing released memory  
would immediately result into a crash. I cannot seem to find a similar  
feature in gdb. Does gdb have any settings, that I can try?

Many thanks in advance for any help.

Best regards

Rolf Jansen