Traceback of pytest failure

File "C:\Program Files (x86)\JetBrains\PyCharm Community Edition 4.0.3\helpers\pycharm\pytestrunner.py", line 58, in <module>
    main()
  File "C:\Program Files (x86)\JetBrains\PyCharm Community Edition 4.0.3\helpers\pycharm\pytestrunner.py", line 32, in main
    exitstatus = hook.pytest_cmdline_main(config=config)
  File "C:\Miniconda\envs\guga\lib\site-packages\_pytest\core.py", line 413, in __call__
    return self._docall(methods, kwargs)
  File "C:\Miniconda\envs\guga\lib\site-packages\_pytest\core.py", line 424, in _docall
    res = mc.execute()
  File "C:\Miniconda\envs\guga\lib\site-packages\_pytest\core.py", line 315, in execute
    res = method(**kwargs)
  File "C:\Miniconda\envs\guga\lib\site-packages\_pytest\main.py", line 116, in pytest_cmdline_main
    return wrap_session(config, _main)
  File "C:\Miniconda\envs\guga\lib\site-packages\_pytest\main.py", line 84, in wrap_session
    doit(config, session)
  File "C:\Miniconda\envs\guga\lib\site-packages\_pytest\main.py", line 122, in _main
    config.hook.pytest_runtestloop(session=session)
  File "C:\Miniconda\envs\guga\lib\site-packages\_pytest\core.py", line 413, in __call__
    return self._docall(methods, kwargs)
  File "C:\Miniconda\envs\guga\lib\site-packages\_pytest\core.py", line 424, in _docall
    res = mc.execute()
  File "C:\Miniconda\envs\guga\lib\site-packages\_pytest\core.py", line 315, in execute
    res = method(**kwargs)
  File "C:\Miniconda\envs\guga\lib\site-packages\_pytest\main.py", line 142, in pytest_runtestloop
    item.config.hook.pytest_runtest_protocol(item=item, nextitem=nextitem)
  File "C:\Miniconda\envs\guga\lib\site-packages\_pytest\core.py", line 413, in __call__
    return self._docall(methods, kwargs)
  File "C:\Miniconda\envs\guga\lib\site-packages\_pytest\core.py", line 424, in _docall
    res = mc.execute()
  File "C:\Miniconda\envs\guga\lib\site-packages\_pytest\core.py", line 315, in execute
    res = method(**kwargs)
  File "C:\Miniconda\envs\guga\lib\site-packages\_pytest\runner.py", line 65, in pytest_runtest_protocol
    runtestprotocol(item, nextitem=nextitem)
  File "C:\Miniconda\envs\guga\lib\site-packages\_pytest\runner.py", line 75, in runtestprotocol
    reports.append(call_and_report(item, "call", log))
  File "C:\Miniconda\envs\guga\lib\site-packages\_pytest\runner.py", line 109, in call_and_report
    call = call_runtest_hook(item, when, **kwds)
  File "C:\Miniconda\envs\guga\lib\site-packages\_pytest\runner.py", line 127, in call_runtest_hook
    return CallInfo(lambda: ihook(item=item, **kwds), when=when)
  File "C:\Miniconda\envs\guga\lib\site-packages\_pytest\runner.py", line 139, in __init__
    self.result = func()
  File "C:\Miniconda\envs\guga\lib\site-packages\_pytest\runner.py", line 127, in <lambda>
    return CallInfo(lambda: ihook(item=item, **kwds), when=when)
  File "C:\Miniconda\envs\guga\lib\site-packages\_pytest\main.py", line 167, in call_matching_hooks
    return hookmethod.pcall(plugins, **kwargs)
  File "C:\Miniconda\envs\guga\lib\site-packages\_pytest\core.py", line 417, in pcall
    return self._docall(methods, kwargs)
  File "C:\Miniconda\envs\guga\lib\site-packages\_pytest\core.py", line 424, in _docall
    res = mc.execute()
  File "C:\Miniconda\envs\guga\lib\site-packages\_pytest\core.py", line 315, in execute
    res = method(**kwargs)
  File "C:\Miniconda\envs\guga\lib\site-packages\_pytest\runner.py", line 89, in pytest_runtest_call
    item.runtest()
  File "C:\Miniconda\envs\guga\lib\site-packages\_pytest\python.py", line 1128, in runtest
    self.ihook.pytest_pyfunc_call(pyfuncitem=self)
  File "C:\Miniconda\envs\guga\lib\site-packages\_pytest\main.py", line 167, in call_matching_hooks
    return hookmethod.pcall(plugins, **kwargs)
  File "C:\Miniconda\envs\guga\lib\site-packages\_pytest\core.py", line 417, in pcall
    return self._docall(methods, kwargs)
  File "C:\Miniconda\envs\guga\lib\site-packages\_pytest\core.py", line 424, in _docall
    res = mc.execute()
  File "C:\Miniconda\envs\guga\lib\site-packages\_pytest\core.py", line 315, in execute
    res = method(**kwargs)
  File "C:\Miniconda\envs\guga\lib\site-packages\_pytest\python.py", line 196, in pytest_pyfunc_call
    testfunction(**testargs)
  File "F:\muenz\personal\projects\src\test_pretty_printer_screws_up_representation.py", line 21, in test_pretty_printer_screws_up_representation
    assert {UnsortableKey('1'), UnsortableKey('2')} == {UnsortableKey('2')}
  File "C:\Miniconda\envs\guga\lib\site-packages\_pytest\assertion\rewrite.py", line 396, in _call_reprcompare
    custom = util._reprcompare(ops[i], each_obj[i], each_obj[i + 1])
  File "C:\Miniconda\envs\guga\lib\site-packages\_pytest\assertion\__init__.py", line 113, in callbinrepr
    config=item.config, op=op, left=left, right=right)
  File "C:\Miniconda\envs\guga\lib\site-packages\_pytest\main.py", line 167, in call_matching_hooks
    return hookmethod.pcall(plugins, **kwargs)
  File "C:\Miniconda\envs\guga\lib\site-packages\_pytest\core.py", line 417, in pcall
    return self._docall(methods, kwargs)
  File "C:\Miniconda\envs\guga\lib\site-packages\_pytest\core.py", line 424, in _docall
    res = mc.execute()
  File "C:\Miniconda\envs\guga\lib\site-packages\_pytest\core.py", line 315, in execute
    res = method(**kwargs)
  File "C:\Miniconda\envs\guga\lib\site-packages\_pytest\assertion\util.py", line 159, in assertrepr_compare
    expl = _compare_eq_iterable(left, right, verbose)
  File "C:\Miniconda\envs\guga\lib\site-packages\_pytest\assertion\util.py", line 226, in _compare_eq_iterable
    left = pprint.pformat(left).splitlines()
  File "C:\Miniconda\envs\guga\lib\pprint.py", line 63, in pformat
    return PrettyPrinter(indent=indent, width=width, depth=depth).pformat(object)
  File "C:\Miniconda\envs\guga\lib\pprint.py", line 122, in pformat
    self._format(object, sio, 0, 0, {}, 0)
  File "C:\Miniconda\envs\guga\lib\pprint.py", line 199, in _format
    object = _sorted(object)
  File "C:\Miniconda\envs\guga\lib\pprint.py", line 82, in _sorted
    return sorted(iterable)
  File "F:\muenz\personal\projects\src\test_pretty_printer_screws_up_representation.py", line 8, in __lt__
    traceback.print_stack()