test#except027 added. It is probably due to the unsafe buffer.
On Windows, I didn't get crash when:
Execute system with arguments 10000 100 (depth 10000, iteration count 100).
   Usually crashes with seg fault in routine called from `last_exception'
   in except.c.

I even changed arguments to 100000 100, I got a crash of stack overflow. After that I ten times the stack size to be 50000000 (50M). The crash was gone.