def test_config_cmdline_options(): 

       o = py.test.ensuretemp('configoptions') 

       o.ensure("conftest.py").write(py.code.Source(""" 

           import py

           def _callback(option, opt_str, value, parser, *args, **kwargs):

               option.tdest = True

           Option = py.test.config.Option

           option = py.test.config.addoptions("testing group", 

               Option('-G', '--glong', action="store", default=42,

                      type="int", dest="gdest", help="g value."), 

               # XXX note: special case, option without a destination

               Option('-T', '--tlong', action="callback", callback=_callback,

                       help='t value'),

               )

           """))

->     old = o.chdir() 

       try: 

           config = py.test.config._reparse(['-G', '17'])

       finally: 

           old.chdir() 

       assert config.option.gdest == 17