Asyncio watcher 'MultiLoopChildWatcher' currently doesn't work well on Solaris and can freeze the event loop indefinitely. This was reported upstream: https://bugs.python.org/issue37573 --- Python-3.12.1/Lib/asyncio/unix_events.py.orig +++ Python-3.12.1/Lib/asyncio/unix_events.py @@ -30,7 +30,7 @@ 'SelectorEventLoop', 'AbstractChildWatcher', 'SafeChildWatcher', 'FastChildWatcher', 'PidfdChildWatcher', - 'MultiLoopChildWatcher', 'ThreadedChildWatcher', + 'ThreadedChildWatcher', 'DefaultEventLoopPolicy', )