I tried hacking tasks.py (After revert back to Python 3.8.5), it
didn't work: Error disappeared, but essentially the program execution
freezed.

def _done_callback(fut):
        ... more ...

        try: outer
        except NameError: outer = None
        if outer is None or outer.done():
            if not fut.cancelled():
                # Mark exception retrieved.
                fut.exception()
            return
    ... more code here ...

    arg_to_fut = {}
    children = []
    nfuts = 0
    nfinished = 0
    outer = None    =============> added
    for arg in coros_or_futures:
        if arg not in arg_to_fut:
            fut = ensure_future(arg, loop=loop)

Reference: https://github.com/python/cpython/pull/31441/files

On Sat, Feb 26, 2022 at 3:44 PM Norman Fung <report@bugs.python.org> wrote:

>
> Norman Fung <norman.lm.fung@gmail.com> added the comment:
>
> Also, i reverted back to python 3.8.5 and overwrote task.py as recommended.
> I think that version we dont already have "GenericAlias".
>
>     import asyncio
>   File "C:\ProgramData\Anaconda3\lib\asyncio\__init__.py", line 8, in
> <module>
>     from .base_events import *
>   File "C:\ProgramData\Anaconda3\lib\asyncio\base_events.py", line 45, in
> <module>
>     from . import staggered
>   File "C:\ProgramData\Anaconda3\lib\asyncio\staggered.py", line 11, in
> <module>
>     from . import tasks
>   File "C:\ProgramData\Anaconda3\lib\asyncio\tasks.py", line 20, in
> <module>
>     from types import GenericAlias
> ImportError: cannot import name 'GenericAlias' from 'types'
> (C:\ProgramData\Anaconda3\lib\types.py)
>
> On Sat, Feb 26, 2022 at 3:20 PM Norman Fung <report@bugs.python.org>
> wrote:
>
> >
> > Norman Fung <norman.lm.fung@gmail.com> added the comment:
> >
> > Thanks Andrew for heads up.
> >
> > *1. My laptop (Windows 10) *with no changes runs happily with no error
> from
> > here.
> >     python 3.8.5
> >     asyncio 3.4.3
> >
> > 2. *My Windows VM (AWS EC2)* is where the whole mess is happening. I
> > *upgraded
> > *from Python 3.8.5 to 3.9.7. Asynio stayed 3.4.3, no change.
> >
> > I manually overwrite C:\ProgramData\Anaconda3\Lib\asyncio\task.py with
> > what's here https://github.com/python/cpython/pull/31441/files
> > (Only
> >
> >
> https://github.com/asvetlov/cpython/blob/150ef068c77abc6a5e7ba97397ac65113dba355a/Lib/asyncio/tasks.py
> > )
> >
> > Before I made this change, the error was:
> >   File "src\xxx\xxx.py", line 37, in _invoke_runners
> >     one_loop.run_until_complete(runner.xxx(xxx, xxx))
> >   File "C:\ProgramData\Anaconda3\lib\site-packages\nest_asyncio.py", line
> > 90, in run_until_complete
> >     self._run_once()
> >   File "C:\ProgramData\Anaconda3\lib\site-packages\nest_asyncio.py", line
> > 127, in _run_once
> >     handle._run()
> >   File "C:\ProgramData\Anaconda3\lib\site-packages\nest_asyncio.py", line
> > 196, in run
> >     ctx.run(self._callback, *self._args)
> >   File "C:\ProgramData\Anaconda3\lib\asyncio\futures.py", line 356, in
> > _set_state
> >     _copy_future_state(other, future)
> >   File "C:\ProgramData\Anaconda3\lib\asyncio\futures.py", line 335, in
> > _copy_future_state
> >     dest.set_result(result)
> >   File "C:\ProgramData\Anaconda3\lib\asyncio\futures.py", line 237, in
> > set_result
> >     self.__schedule_callbacks()
> >   File "C:\ProgramData\Anaconda3\lib\asyncio\futures.py", line 149, in
> > __schedule_callbacks
> >     self._loop.call_soon(callback, self, context=ctx)
> > Traceback (most recent call last):
> >   File "C:\ProgramData\Anaconda3\lib\site-packages\nest_asyncio.py", line
> > 196, in run
> >     ctx.run(self._callback, *self._args)
> >   File "C:\ProgramData\Anaconda3\lib\asyncio\tasks.py", line 762, in
> > _done_callback
> >     if outer.done():
> > NameError: free variable 'outer' referenced before assignment in
> enclosing
> > scope
> >
> > After I upgraded python to 3.9.7 and overwrite task.py, a different error
> > (but also in asyncio stack):
> >
> > 2022-02-26 06:48:27,047 casin0: @slack algo_order.id: 13 #8 Algo tick
> > level
> > error casin0 uat <class 'RuntimeError'> Non-thread-safe operation invoked
> > on an event loop other than the current one Traceback (most recent call
> > last):
> >   File "C:\dev\xxx.py", line 547, in xxx
> >     await asyncio.sleep(algo.param.interval_ms / 1000)
> >   File "C:\ProgramData\Anaconda3\lib\asyncio\tasks.py", line 651, in
> sleep
> >     h = loop.call_later(delay,
> >   File "C:\ProgramData\Anaconda3\lib\asyncio\base_events.py", line 714,
> in
> > call_later
> >     timer = self.call_at(self.time() + delay, callback, *args,
> >   File "C:\ProgramData\Anaconda3\lib\asyncio\base_events.py", line 727,
> in
> > call_at
> >     self._check_thread()
> >   File "C:\ProgramData\Anaconda3\lib\asyncio\base_events.py", line 785,
> in
> > _check_thread
> >     raise RuntimeError(
> > RuntimeError: Non-thread-safe operation invoked on an event loop other
> than
> > the current one
> >
> > On Sat, Feb 26, 2022 at 2:36 PM Andrew Svetlov <report@bugs.python.org>
> > wrote:
> >
> > >
> > > Andrew Svetlov <andrew.svetlov@gmail.com> added the comment:
> > >
> > > Also, fix is 1 week old. There are no python releases with the fix
> > > included yet.
> > >
> > > On Sat, Feb 26, 2022, 06:58 Norman Fung <report@bugs.python.org>
> wrote:
> > >
> > > >
> > > > Norman Fung <norman.lm.fung@gmail.com> added the comment:
> > > >
> > > > Thanks Jelle, let me try upgrade first.
> > > >
> > > > Norman
> > > >
> > > > On Sat, Feb 26, 2022 at 9:27 AM Jelle Zijlstra <
> report@bugs.python.org
> > >
> > > > wrote:
> > > >
> > > > >
> > > > > Jelle Zijlstra <jelle.zijlstra@gmail.com> added the comment:
> > > > >
> > > > > 3.8 is only receiving security fixes now. Please upgrade. If you
> > cannot
> > > > > upgrade, I suggest manually applying the patch from
> > > > > https://github.com/python/cpython/pull/31441/files to your
> > > installation
> > > > > of Python.
> > > > >
> > > > > ----------
> > > > > nosy: +Jelle Zijlstra
> > > > > resolution:  -> out of date
> > > > > stage:  -> resolved
> > > > > status: open -> closed
> > > > >
> > > > > _______________________________________
> > > > > Python tracker <report@bugs.python.org>
> > > > > <https://bugs.python.org/issue46859>
> > > > > _______________________________________
> > > > >
> > > >
> > > > ----------
> > > >
> > > > _______________________________________
> > > > Python tracker <report@bugs.python.org>
> > > > <https://bugs.python.org/issue46859>
> > > > _______________________________________
> > > >
> > >
> > > ----------
> > >
> > > _______________________________________
> > > Python tracker <report@bugs.python.org>
> > > <https://bugs.python.org/issue46859>
> > > _______________________________________
> > >
> >
> > ----------
> >
> > _______________________________________
> > Python tracker <report@bugs.python.org>
> > <https://bugs.python.org/issue46859>
> > _______________________________________
> >
>
> ----------
>
> _______________________________________
> Python tracker <report@bugs.python.org>
> <https://bugs.python.org/issue46859>
> _______________________________________
>