Home Original page

Error with console output in Python 3.6 on Windows

When running pytest in Python 3.6rc2 on Windows, there seems to be a problem with formatting the console output. The tests run fine until at some point it crashes because of a OSError: [WinError 87] The parameter is incorrect. This does not happen if I pipe the output into a file instead of having it in the console. I am not sure whether that is an issue with the py._io.TerminalWriter or something else. Since the 3.6 version is also not stable yet, so the issue might be there.

Traceback (most recent call last):
  File "C:\Program Files\Python36\lib\site-packages\_pytest\main.py", line 98, in wrap_session
    session.exitstatus = doit(config, session) or 0
  File "C:\Program Files\Python36\lib\site-packages\_pytest\main.py", line 133, in _main
    config.hook.pytest_runtestloop(session=session)
  File "C:\Program Files\Python36\lib\site-packages\_pytest\vendored_packages\pluggy.py", line 745, in __call__
    return self._hookexec(self, self._nonwrappers + self._wrappers, kwargs)
  File "C:\Program Files\Python36\lib\site-packages\_pytest\vendored_packages\pluggy.py", line 339, in _hookexec
    return self._inner_hookexec(hook, methods, kwargs)
  File "C:\Program Files\Python36\lib\site-packages\_pytest\vendored_packages\pluggy.py", line 334, in <lambda>
    _MultiCall(methods, kwargs, hook.spec_opts).execute()
  File "C:\Program Files\Python36\lib\site-packages\_pytest\vendored_packages\pluggy.py", line 614, in execute
    res = hook_impl.function(*args)
  File "C:\Program Files\Python36\lib\site-packages\_pytest\main.py", line 154, in pytest_runtestloop
    item.config.hook.pytest_runtest_protocol(item=item, nextitem=nextitem)
  File "C:\Program Files\Python36\lib\site-packages\_pytest\vendored_packages\pluggy.py", line 745, in __call__
    return self._hookexec(self, self._nonwrappers + self._wrappers, kwargs)
  File "C:\Program Files\Python36\lib\site-packages\_pytest\vendored_packages\pluggy.py", line 339, in _hookexec
    return self._inner_hookexec(hook, methods, kwargs)
  File "C:\Program Files\Python36\lib\site-packages\_pytest\vendored_packages\pluggy.py", line 334, in <lambda>
    _MultiCall(methods, kwargs, hook.spec_opts).execute()
  File "C:\Program Files\Python36\lib\site-packages\_pytest\vendored_packages\pluggy.py", line 613, in execute
    return _wrapped_call(hook_impl.function(*args), self.execute)
  File "C:\Program Files\Python36\lib\site-packages\_pytest\vendored_packages\pluggy.py", line 254, in _wrapped_call
    return call_outcome.get_result()
  File "C:\Program Files\Python36\lib\site-packages\_pytest\vendored_packages\pluggy.py", line 279, in get_result
    raise ex[1].with_traceback(ex[2])
  File "C:\Program Files\Python36\lib\site-packages\_pytest\vendored_packages\pluggy.py", line 265, in __init__
    self.result = func()
  File "C:\Program Files\Python36\lib\site-packages\_pytest\vendored_packages\pluggy.py", line 614, in execute
    res = hook_impl.function(*args)
  File "C:\Program Files\Python36\lib\site-packages\_pytest\runner.py", line 66, in pytest_runtest_protocol
    runtestprotocol(item, nextitem=nextitem)
  File "C:\Program Files\Python36\lib\site-packages\_pytest\runner.py", line 79, in runtestprotocol
    reports.append(call_and_report(item, "call", log))
  File "C:\Program Files\Python36\lib\site-packages\_pytest\runner.py", line 137, in call_and_report
    hook.pytest_runtest_logreport(report=report)
  File "C:\Program Files\Python36\lib\site-packages\_pytest\vendored_packages\pluggy.py", line 745, in __call__
    return self._hookexec(self, self._nonwrappers + self._wrappers, kwargs)
  File "C:\Program Files\Python36\lib\site-packages\_pytest\vendored_packages\pluggy.py", line 339, in _hookexec
    return self._inner_hookexec(hook, methods, kwargs)
  File "C:\Program Files\Python36\lib\site-packages\_pytest\vendored_packages\pluggy.py", line 334, in <lambda>
    _MultiCall(methods, kwargs, hook.spec_opts).execute()
  File "C:\Program Files\Python36\lib\site-packages\_pytest\vendored_packages\pluggy.py", line 614, in execute
    res = hook_impl.function(*args)
  File "C:\Program Files\Python36\lib\site-packages\_pytest\terminal.py", line 207, in pytest_runtest_logreport
    self.write_fspath_result(rep.nodeid, letter)
  File "C:\Program Files\Python36\lib\site-packages\_pytest\terminal.py", line 123, in write_fspath_result
    self._tw.write(res)
  File "C:\Program Files\Python36\lib\site-packages\py\_io\terminalwriter.py", line 207, in write
    write_out(self._file, markupmsg)
  File "C:\Program Files\Python36\lib\site-packages\py\_io\terminalwriter.py", line 342, in write_out
    fil.write(msg)
  File "C:\Program Files\Python36\lib\site-packages\colorama\ansitowin32.py", line 40, in write
    self.__convertor.write(text)
  File "C:\Program Files\Python36\lib\site-packages\colorama\ansitowin32.py", line 141, in write
    self.write_and_convert(text)
  File "C:\Program Files\Python36\lib\site-packages\colorama\ansitowin32.py", line 169, in write_and_convert
    self.write_plain_text(text, cursor, len(text))
  File "C:\Program Files\Python36\lib\site-packages\colorama\ansitowin32.py", line 175, in write_plain_text
    self.wrapped.flush()
OSError: [WinError 87] The parameter is incorrect

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:\Program Files\Python36\lib\site-packages\_pytest\main.py", line 111, in wrap_session
    config.notify_exception(excinfo, config.option)
  File "C:\Program Files\Python36\lib\site-packages\_pytest\config.py", line 923, in notify_exception
    excinfo=excinfo)
  File "C:\Program Files\Python36\lib\site-packages\_pytest\vendored_packages\pluggy.py", line 745, in __call__
    return self._hookexec(self, self._nonwrappers + self._wrappers, kwargs)
  File "C:\Program Files\Python36\lib\site-packages\_pytest\vendored_packages\pluggy.py", line 339, in _hookexec
    return self._inner_hookexec(hook, methods, kwargs)
  File "C:\Program Files\Python36\lib\site-packages\_pytest\vendored_packages\pluggy.py", line 334, in <lambda>
    _MultiCall(methods, kwargs, hook.spec_opts).execute()
  File "C:\Program Files\Python36\lib\site-packages\_pytest\vendored_packages\pluggy.py", line 614, in execute
    res = hook_impl.function(*args)
  File "C:\Program Files\Python36\lib\site-packages\_pytest\terminal.py", line 164, in pytest_internalerror
    self.write_line("INTERNALERROR> " + line)
  File "C:\Program Files\Python36\lib\site-packages\_pytest\terminal.py", line 145, in write_line
    self.ensure_newline()
  File "C:\Program Files\Python36\lib\site-packages\_pytest\terminal.py", line 136, in ensure_newline
    self._tw.line()
  File "C:\Program Files\Python36\lib\site-packages\py\_io\terminalwriter.py", line 212, in line
    self.write('\n')
  File "C:\Program Files\Python36\lib\site-packages\py\_io\terminalwriter.py", line 207, in write
    write_out(self._file, markupmsg)
  File "C:\Program Files\Python36\lib\site-packages\py\_io\terminalwriter.py", line 342, in write_out
    fil.write(msg)
  File "C:\Program Files\Python36\lib\site-packages\colorama\ansitowin32.py", line 40, in write
    self.__convertor.write(text)
  File "C:\Program Files\Python36\lib\site-packages\colorama\ansitowin32.py", line 141, in write
    self.write_and_convert(text)
  File "C:\Program Files\Python36\lib\site-packages\colorama\ansitowin32.py", line 169, in write_and_convert
    self.write_plain_text(text, cursor, len(text))
  File "C:\Program Files\Python36\lib\site-packages\colorama\ansitowin32.py", line 174, in write_plain_text
    self.wrapped.write(text[start:end])
OSError: [WinError 87] The parameter is incorrect

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:\Program Files\Python36\lib\runpy.py", line 193, in _run_module_as_main
    "__main__", mod_spec)
  File "C:\Program Files\Python36\lib\runpy.py", line 85, in _run_code
    exec(code, run_globals)
  File "C:\Program Files\Python36\lib\site-packages\pytest.py", line 17, in <module>
    raise SystemExit(pytest.main())
  File "C:\Program Files\Python36\lib\site-packages\_pytest\config.py", line 57, in main
    return config.hook.pytest_cmdline_main(config=config)
  File "C:\Program Files\Python36\lib\site-packages\_pytest\vendored_packages\pluggy.py", line 745, in __call__
    return self._hookexec(self, self._nonwrappers + self._wrappers, kwargs)
  File "C:\Program Files\Python36\lib\site-packages\_pytest\vendored_packages\pluggy.py", line 339, in _hookexec
    return self._inner_hookexec(hook, methods, kwargs)
  File "C:\Program Files\Python36\lib\site-packages\_pytest\vendored_packages\pluggy.py", line 334, in <lambda>
    _MultiCall(methods, kwargs, hook.spec_opts).execute()
  File "C:\Program Files\Python36\lib\site-packages\_pytest\vendored_packages\pluggy.py", line 614, in execute
    res = hook_impl.function(*args)
  File "C:\Program Files\Python36\lib\site-packages\_pytest\main.py", line 127, in pytest_cmdline_main
    return wrap_session(config, _main)
  File "C:\Program Files\Python36\lib\site-packages\_pytest\main.py", line 122, in wrap_session
    exitstatus=session.exitstatus)
  File "C:\Program Files\Python36\lib\site-packages\_pytest\vendored_packages\pluggy.py", line 745, in __call__
    return self._hookexec(self, self._nonwrappers + self._wrappers, kwargs)
  File "C:\Program Files\Python36\lib\site-packages\_pytest\vendored_packages\pluggy.py", line 339, in _hookexec
    return self._inner_hookexec(hook, methods, kwargs)
  File "C:\Program Files\Python36\lib\site-packages\_pytest\vendored_packages\pluggy.py", line 334, in <lambda>
    _MultiCall(methods, kwargs, hook.spec_opts).execute()
  File "C:\Program Files\Python36\lib\site-packages\_pytest\vendored_packages\pluggy.py", line 613, in execute
    return _wrapped_call(hook_impl.function(*args), self.execute)
  File "C:\Program Files\Python36\lib\site-packages\_pytest\vendored_packages\pluggy.py", line 250, in _wrapped_call
    wrap_controller.send(call_outcome)
  File "C:\Program Files\Python36\lib\site-packages\_pytest\terminal.py", line 359, in pytest_sessionfinish
    self._tw.line("")
  File "C:\Program Files\Python36\lib\site-packages\py\_io\terminalwriter.py", line 212, in line
    self.write('\n')
  File "C:\Program Files\Python36\lib\site-packages\py\_io\terminalwriter.py", line 207, in write
    write_out(self._file, markupmsg)
  File "C:\Program Files\Python36\lib\site-packages\py\_io\terminalwriter.py", line 342, in write_out
    fil.write(msg)
  File "C:\Program Files\Python36\lib\site-packages\colorama\ansitowin32.py", line 40, in write
    self.__convertor.write(text)
  File "C:\Program Files\Python36\lib\site-packages\colorama\ansitowin32.py", line 141, in write
    self.write_and_convert(text)
  File "C:\Program Files\Python36\lib\site-packages\colorama\ansitowin32.py", line 169, in write_and_convert
    self.write_plain_text(text, cursor, len(text))
  File "C:\Program Files\Python36\lib\site-packages\colorama\ansitowin32.py", line 174, in write_plain_text
    self.wrapped.write(text[start:end])
OSError: [WinError 87] The parameter is incorrect
Exception ignored in: <_io.TextIOWrapper name='<stdout>' mode='w' encoding='utf-8'>
OSError: [WinError 87] The parameter is incorrect