[Help wanted, macOS] prompt_toolkit/input/vt100.py: `OSError: [Errno 45] Operation not supported`

[barracuda156]

Something does not work on macOS < 10.6.8 which leaves dependents of prompt-toolkit defunct.
The issue does not exist on 10.6.8, whether on x86, Rosetta or native powerpc.

I understand that 10.5 is old and there may not be much interest to support it and add dedicated fixes. So I do not ask to make any changes here in upstream. However, there are users of 10.4–10.5, and affected apps are end-user apps, which are desirable to have working.

Could someone suggest a solution? I can add a local patch into my fork of ports for PowerPC and use it conditionally on macOS version, so nothing gets messed up for 10.6+.

Details are below.

Example with radian:

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

See also: https://trac.macports.org/ticket/67046

Example with fastanime:

PMG5:~ matias$ fastanime --trace anilist
[bold yellow]Welcome to FastAnime![/bold yellow] No configuration file found.
Traceback (most recent call last):
  File "/opt/local/bin/fastanime", line 8, in <module>
    sys.exit(Cli())
             ~~~^^
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.13/lib/python3.13/site-packages/fastanime/__init__.py", line 12, in Cli
    run_cli()
    ~~~~~~~^^
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.13/lib/python3.13/site-packages/click/core.py", line 1442, in __call__
    return self.main(*args, **kwargs)
           ~~~~~~~~~^^^^^^^^^^^^^^^^^
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.13/lib/python3.13/site-packages/click/core.py", line 1363, in main
    rv = self.invoke(ctx)
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.13/lib/python3.13/site-packages/click/core.py", line 1827, in invoke
    super().invoke(ctx)
    ~~~~~~~~~~~~~~^^^^^
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.13/lib/python3.13/site-packages/click/core.py", line 1226, in invoke
    return ctx.invoke(self.callback, **ctx.params)
           ~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.13/lib/python3.13/site-packages/click/core.py", line 794, in invoke
    return callback(*args, **kwargs)
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.13/lib/python3.13/site-packages/click/decorators.py", line 34, in new_func
    return f(get_current_context(), *args, **kwargs)
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.13/lib/python3.13/site-packages/fastanime/cli/cli.py", line 106, in cli
    else loader.load(cli_overrides)
         ~~~~~~~~~~~^^^^^^^^^^^^^^^
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.13/lib/python3.13/site-packages/fastanime/cli/config/loader.py", line 88, in load
    return self._handle_first_run()
           ~~~~~~~~~~~~~~~~~~~~~~^^
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.13/lib/python3.13/site-packages/fastanime/cli/config/loader.py", line 55, in _handle_first_run
    ).execute()
      ~~~~~~~^^
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.13/lib/python3.13/site-packages/InquirerPy/base/simple.py", line 330, in execute
    result = self._run()
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.13/lib/python3.13/site-packages/InquirerPy/base/complex.py", line 208, in _run
    return self.application.run()
           ~~~~~~~~~~~~~~~~~~~~^^
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.13/lib/python3.13/site-packages/prompt_toolkit/application/application.py", line 1002, in run
    return asyncio.run(coro)
           ~~~~~~~~~~~^^^^^^
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.13/lib/python3.13/asyncio/runners.py", line 195, in run
    return runner.run(main)
           ~~~~~~~~~~^^^^^^
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.13/lib/python3.13/asyncio/runners.py", line 118, in run
    return self._loop.run_until_complete(task)
           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.13/lib/python3.13/asyncio/base_events.py", line 725, in run_until_complete
    return future.result()
           ~~~~~~~~~~~~~^^
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.13/lib/python3.13/site-packages/prompt_toolkit/application/application.py", line 886, in run_async
    return await _run_async(f)
           ^^^^^^^^^^^^^^^^^^^
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.13/lib/python3.13/site-packages/prompt_toolkit/application/application.py", line 734, in _run_async
    with self.input.raw_mode(), self.input.attach(
                                ~~~~~~~~~~~~~~~~~^
        read_from_input_in_context
        ^^^^^^^^^^^^^^^^^^^^^^^^^^
    ), attach_winch_signal_handler(self._on_resize):
    ^
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.13/lib/python3.13/contextlib.py", line 141, in __enter__
    return next(self.gen)
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.13/lib/python3.13/site-packages/prompt_toolkit/input/vt100.py", line 165, in _attached_input
    loop.add_reader(fd, callback_wrapper)
    ~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.13/lib/python3.13/asyncio/selector_events.py", line 347, in add_reader
    self._add_reader(fd, callback, *args)
    ~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.13/lib/python3.13/asyncio/selector_events.py", line 279, in _add_reader
    self._selector.register(fd, selectors.EVENT_READ,
    ~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^
                            (handle, None))
                            ^^^^^^^^^^^^^^^
  File "/opt/local/Library/Frameworks/Python.framework/Versions/3.13/lib/python3.13/selectors.py", line 505, in register
    self._selector.control([kev], 0, 0)
    ~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^
OSError: [Errno 45] Operation not supported

Reported in https://forums.macrumors.com/threads/ppcports-the-only-ports-you-ever-need-on-a-powerpc.2462897/page-3?post=34091087#post-34091087

P. S. Please do not close the issue immediately; if there is no response for a while, it can be closed as not planned.