Traceback has regressed. import sys def f(): 1/0 try: f() except: tb = sys.exc_info()[2] while tb: print tb.tb_lineno tb = tb.tb_next CPython: 3 2 IronPython 1.1.1: 3 2 IronPython 2.0a5: 2 IronPython 2.0b1: (nothing) This is not 1.x->2.x regression. This is regression between 2.x series. -- Seo Sanghyeon