Either python or py-prompt_toolkit is broken on Leopard: KeyError: '0 is not registered' when trying to run dependents

[barracuda156]

Example is with trying to run ptpython, however the error is not in it, since another port, radian, also depending on py-prompt_toolkit, fails identically.

Last login: Mon Mar  6 04:05:32 on ttys000
36-137:~ svacchanda$ ptpython
Traceback (most recent call last):
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/asyncio/selector_events.py", line 256, in _add_reader
    key = self._selector.get_key(fd)
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/selectors.py", line 193, in get_key
    raise KeyError("{!r} is not registered".format(fileobj)) from None
KeyError: '0 is not registered'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/ptpython/repl.py", line 135, in run
    text = self.read()
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/ptpython/python_input.py", line 1045, in read
    result = self.app.run(pre_run=pre_run, in_thread=True)
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/prompt_toolkit/application/application.py", line 961, in run
    raise exception
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/prompt_toolkit/application/application.py", line 939, in run_in_thread
    result = self.run(
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/prompt_toolkit/application/application.py", line 978, in run
    return loop.run_until_complete(
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/asyncio/base_events.py", line 649, in run_until_complete
    return future.result()
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/prompt_toolkit/application/application.py", line 885, in run_async
    return await _run_async(f)
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/prompt_toolkit/application/application.py", line 737, in _run_async
    with self.input.raw_mode(), self.input.attach(
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/contextlib.py", line 135, in __enter__
    return next(self.gen)
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/site-packages/prompt_toolkit/input/vt100.py", line 176, in _attached_input
    loop.add_reader(fd, callback_wrapper)
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/asyncio/selector_events.py", line 331, in add_reader
    self._add_reader(fd, callback, *args)
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/asyncio/selector_events.py", line 258, in _add_reader
    self._selector.register(fd, selectors.EVENT_READ,
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/selectors.py", line 523, in register
    self._selector.control([kev], 0, 0)
OSError: [Errno 45] Operation not supported
Traceback (most recent call last):
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/asyncio/selector_events.py", line 256, in _add_reader
    key = self._selector.get_key(fd)
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/selectors.py", line 193, in get_key
    raise KeyError("{!r} is not registered".format(fileobj)) from None
KeyError: '0 is not registered'

This repeats in a loop then. Initially I faced the error on 10.6, however it is now confirmed on 10.5.8, so I can open a legitimate ticket.