FAILED terminado/tests/basic_test.py::UniqueTermTests::test_max_terminals - tornado.simple_httpclient.HTTPStreamClosedError: Stream closed w/ py3.8

[mgorny]

On Python 3.8, the same test fails with a different failure/error:

$ python3.8 -m pytest
=============================================================== test session starts ===============================================================
platform linux -- Python 3.8.3, pytest-5.4.3, py-1.8.0, pluggy-0.13.1
rootdir: /tmp/terminado
plugins: requests-mock-1.7.0, betamax-0.8.1, timeout-1.3.4, httpbin-1.0.0, xprocess-0.13.1, forked-1.1.3, xdist-1.32.0, shutil-1.7.0, virtualenv-1.7.0, expect-1.1.0, localserver-0.5.0, services-2.0.1, backports.unittest-mock-1.5, mock-3.1.1, pyfakefs-3.7.2, flaky-3.6.1, hypothesis-5.16.0
collected 8 items                                                                                                                                 

terminado/tests/basic_test.py ......FE.                                                                                                     [100%]

===================================================================== ERRORS ======================================================================
_____________________________________________ ERROR at teardown of UniqueTermTests.test_max_terminals _____________________________________________
/usr/lib/python3.8/site-packages/tornado/testing.py:466: in tearDown
    self.io_loop.run_sync(
/usr/lib/python3.8/site-packages/tornado/ioloop.py:532: in run_sync
    return future_cell[0].result()
/usr/lib/python3.8/site-packages/tornado/httpserver.py:221: in close_all_connections
    await conn.close()
/usr/lib/python3.8/site-packages/tornado/http1connection.py:789: in close
    self.stream.close()
/usr/lib/python3.8/site-packages/tornado/iostream.py:624: in close
    self.close_fd()
/usr/lib/python3.8/site-packages/tornado/iostream.py:1149: in close_fd
    self.socket.close()
/usr/lib/python3.8/socket.py:500: in close
    self._real_close()
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

self = <socket.socket [closed] fd=-1, family=AddressFamily.AF_INET, type=SocketKind.SOCK_STREAM, proto=6>, _ss = <class '_socket.socket'>

    def _real_close(self, _ss=_socket.socket):
        # This function should not reference any globals. See issue #808164.
>       _ss.close(self)
E       OSError: [Errno 9] Bad file descriptor

/usr/lib/python3.8/socket.py:494: OSError
---------------------------------------------------------------- Captured log call ----------------------------------------------------------------
WARNING  tornado.general:autoreload.py:129 tornado.autoreload started more than once in the same process
==================================================================== FAILURES =====================================================================
_______________________________________________________ UniqueTermTests.test_max_terminals ________________________________________________________

self = <terminado.tests.basic_test.UniqueTermTests testMethod=test_max_terminals>

    @tornado.testing.gen_test
    def test_max_terminals(self):
>       tms = yield self.get_term_clients(['/unique'] * MAX_TERMS)

terminado/tests/basic_test.py:227: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
/usr/lib/python3.8/site-packages/tornado/gen.py:735: in run
    value = future.result()
/usr/lib/python3.8/site-packages/tornado/gen.py:742: in run
    yielded = self.gen.throw(*exc_info)  # type: ignore
terminado/tests/basic_test.py:114: in get_term_clients
    tms = yield [self.get_term_client(path) for path in paths]
/usr/lib/python3.8/site-packages/tornado/gen.py:735: in run
    value = future.result()
/usr/lib/python3.8/site-packages/tornado/gen.py:501: in callback
    result_list.append(f.result())
/usr/lib/python3.8/site-packages/tornado/gen.py:742: in run
    yielded = self.gen.throw(*exc_info)  # type: ignore
terminado/tests/basic_test.py:109: in get_term_client
    ws = yield tornado.websocket.websocket_connect(request)
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

self = <tornado.gen.Runner object at 0x7f4dc8fcb160>

    def run(self) -> None:
        """Starts or resumes the generator, running until it reaches a
        yield point that is not ready.
        """
        if self.running or self.finished:
            return
        try:
            self.running = True
            while True:
                future = self.future
                if future is None:
                    raise Exception("No pending future")
                if not future.done():
                    return
                self.future = None
                try:
                    exc_info = None
    
                    try:
>                       value = future.result()
E                       tornado.simple_httpclient.HTTPStreamClosedError: Stream closed

/usr/lib/python3.8/site-packages/tornado/gen.py:735: HTTPStreamClosedError
---------------------------------------------------------------- Captured log call ----------------------------------------------------------------
WARNING  tornado.general:autoreload.py:129 tornado.autoreload started more than once in the same process
================================================================ warnings summary =================================================================
terminado/tests/basic_test.py:32
  /tmp/terminado/terminado/tests/basic_test.py:32: PytestCollectionWarning: cannot collect test class 'TestTermClient' because it has a __init__ constructor (from: terminado/tests/basic_test.py)
    class TestTermClient(object):

-- Docs: https://docs.pytest.org/en/latest/warnings.html
============================================================= short test summary info =============================================================
FAILED terminado/tests/basic_test.py::UniqueTermTests::test_max_terminals - tornado.simple_httpclient.HTTPStreamClosedError: Stream closed
ERROR terminado/tests/basic_test.py::UniqueTermTests::test_max_terminals - OSError: [Errno 9] Bad file descriptor
================================================ 1 failed, 7 passed, 1 warning, 1 error in 35.89s =================================================