"tornado.curl_httpclient.CurlError: HTTP 599: Failed writing header" after updating to python 3.10 on alpine 3.15

[ghevge]

Hi,
Recently I've updated my tornado tests container to python:3.10-alpine3.15 from python:3.9.6-alpine3.14. After doing this, my tests started to fail with the error below.

These are my dependencies:

coverage==5.3
pytest==6.2.4
pytest-cov==2.10.1
pytest-rerunfailures==10.1
redislite==5.0.142319
pytest-mock==3.6.1
pytest-tornado==0.8.1
ptvsd==4.2.7
pytest-xdist==2.3.0
aiohttp==3.7.4.post0
SQLAlchemy==1.4.22
Deprecated==1.2.11
nest-asyncio==1.5.1
ldap3==2.7
tornado==6.1
alembic==1.6.5
psycopg2==2.9.1
asyncpg==0.23.0
pycurl==7.43.0
cookies==2.2.1
opuslib==3.0.1
redis==3.3.8
apispec==3.3.1
apispec-webframeworks==0.5.2
marshmallow==3.7.0
itsdangerous==1.1.0
sendgrid==5.6.0
grpcio-tools==1.38.1
protoc-gen-swagger==0.1.0
googleapis-common-protos==1.6.0
prometheus_client==0.7.1
jaeger-client==4.3.0
python-dateutil==2.8.1

Any idea what could cause this errors?

Thanks

tests/admin/handlers/data_collection/data_collection_test.py:233: in _create_task
    response = self._fetch(TASKS_URI, body=json.dumps(task), method='POST')
tests/base.py:608: in _fetch
    return self.fetch(*args, **kwargs)
/usr/local/lib/python3.10/site-packages/tornado/testing.py:443: in fetch
    return self.io_loop.run_sync(
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

self = <tornado.platform.asyncio.AsyncIOLoop object at 0x7f43438c2ef0>, func = <function AsyncHTTPTestCase.fetch.<locals>.<lambda> at 0x7f43437497e0>, timeout = 300.0

    def run_sync(self, func: Callable, timeout: Optional[float] = None) -> Any:
        """Starts the `IOLoop`, runs the given function, and stops the loop.
    
        The function must return either an awaitable object or
        ``None``. If the function returns an awaitable object, the
        `IOLoop` will run until the awaitable is resolved (and
        `run_sync()` will return the awaitable's result). If it raises
        an exception, the `IOLoop` will stop and the exception will be
        re-raised to the caller.
    
        The keyword-only argument ``timeout`` may be used to set
        a maximum duration for the function.  If the timeout expires,
        a `tornado.util.TimeoutError` is raised.
    
        This method is useful to allow asynchronous calls in a
        ``main()`` function::
    
            async def main():
                # do stuff...
    
            if __name__ == '__main__':
                IOLoop.current().run_sync(main)
    
        .. versionchanged:: 4.3
           Returning a non-``None``, non-awaitable value is now an error.
    
        .. versionchanged:: 5.0
           If a timeout occurs, the ``func`` coroutine will be cancelled.
    
        """
        future_cell = [None]  # type: List[Optional[Future]]
    
        def run() -> None:
            try:
                result = func()
                if result is not None:
                    from tornado.gen import convert_yielded
    
                    result = convert_yielded(result)
            except Exception:
                fut = Future()  # type: Future[Any]
                future_cell[0] = fut
                future_set_exc_info(fut, sys.exc_info())
            else:
                if is_future(result):
                    future_cell[0] = result
                else:
                    fut = Future()
                    future_cell[0] = fut
                    fut.set_result(result)
            assert future_cell[0] is not None
            self.add_future(future_cell[0], lambda future: self.stop())
    
        self.add_callback(run)
        if timeout is not None:
    
            def timeout_callback() -> None:
                # If we can cancel the future, do so and wait on it. If not,
                # Just stop the loop and return with the task still pending.
                # (If we neither cancel nor wait for the task, a warning
                # will be logged).
                assert future_cell[0] is not None
                if not future_cell[0].cancel():
                    self.stop()
    
            timeout_handle = self.add_timeout(self.time() + timeout, timeout_callback)
        self.start()
        if timeout is not None:
            self.remove_timeout(timeout_handle)
        assert future_cell[0] is not None
        if future_cell[0].cancelled() or not future_cell[0].done():
            raise TimeoutError("Operation timed out after %s seconds" % timeout)
>       return future_cell[0].result()
E       tornado.curl_httpclient.CurlError: HTTP 599: Failed writing header

/usr/local/lib/python3.10/site-packages/tornado/ioloop.py:530: CurlError

[bdarnell]

I have no idea what might be causing this, but I noticed nest-asyncio in your dependencies list, and I'm suspicious of that package. Nesting asyncio event loops in the wrong places could cause all kinds of undefined behavior.