flexx fails with Python 3.14

[edreamleo]

flexx works with Python 3.13 and below in the leo-editor environment. With Python 3.14 it fails during startup as follows:

Traceback (most recent call last):

  File "C:\Repos\leo-editor\leo\core\leoApp.py", line 987, in createBrowserGui
    from flexx import flx

  File "C:\Python\Python3.14\Lib\site-packages\flexx\flx.py", line 9, in <module>
    from .event import *

  File "C:\Python\Python3.14\Lib\site-packages\flexx\event\__init__.py", line 15, in <module>
    from ._loop import Loop, loop

  File "C:\Python\Python3.14\Lib\site-packages\flexx\event\_loop.py", line 480, in <module>
    loop = Loop()

  File "C:\Python\Python3.14\Lib\site-packages\flexx\event\_loop.py", line 47, in __init__
    self.integrate()
    ~~~~~~~~~~~~~~^^

  File "C:\Python\Python3.14\Lib\site-packages\flexx\event\_loop.py", line 389, in integrate
    loop = asyncio.get_event_loop()

  File "C:\Python\Python3.14\Lib\asyncio\events.py", line 715, in get_event_loop
    raise RuntimeError('There is no current event loop in thread %r.'
                       % threading.current_thread().name)

RuntimeError: There is no current event loop in thread 'MainThread'.

can not import flexx

This crash is expected. Python 3.14 changed the API for asyncio.

FYI, Leo PR #4413 fixes Leo's server so that it works with Python 3.13. Similar changes might work for flexx.

[almarklein]

Thanks for reporting this! I'm not actively working on Flexx anymore, but would be good to keep it working for 3.14 and make a new release!

[edreamleo]

@almarklein You're welcome. It's my pleasure.