High level API is broken in 3.14

[griffinmilsap]

Looks like some of the changes in the clean-shutdown PR rely on APIs that were removed from 3.14.

uv sync --all-extras --python=3.14

~/repos/ezmsg feature/process-control* 3m 11s ❯ uv run examples/ezmsg_toy.py
2026-03-17 11:09:37.792 - pid: 25306 - MainThread - INFO - _initialize: Connected to GraphServer @ 127.0.0.1:25978
2026-03-17 11:09:37.795 - pid: 25306 - MainThread - INFO - _initialize: Running in 5 processes.
2026-03-17 11:09:37.900 - pid: 25308 - TaskThread - INFO - wrapped_task: SYSTEM/PING:spawn_once Complete
2026-03-17 11:09:37.900 - pid: 25306 - TaskThread - INFO - wrapped_task: SYSTEM/FOO:spawn_once Complete
2026-03-17 11:09:37.900 - pid: 25311 - TaskThread - INFO - on_message: Output[Default]: Spawned Once
2026-03-17 11:09:37.900 - pid: 25309 - TaskThread - INFO - on_message: Output[REPUB]: CombinedMessage(string='Spawned Once', number=0.0105096721555893)
2026-03-17 11:09:37.900 - pid: 25310 - TaskThread - INFO - on_message: Output[A1]: Spawned Once
2026-03-17 11:09:37.902 - pid: 25310 - MainThread - WARNING - new_threaded_event_loop: Shutdown suppressed 0 error(s) and cancelled 1 task(s). Shutdown was NOT clean; re-run with EZMSG_STRICT_SHUTDOWN=1 to debug tasks with poor shutdown behavior.
Process DefaultBackendProcess-4:
2026-03-17 11:09:37.902 - pid: 25311 - MainThread - WARNING - new_threaded_event_loop: Shutdown suppressed 0 error(s) and cancelled 1 task(s). Shutdown was NOT clean; re-run with EZMSG_STRICT_SHUTDOWN=1 to debug tasks with poor shutdown behavior.
2026-03-17 11:09:37.902 - pid: 25308 - MainThread - WARNING - new_threaded_event_loop: Shutdown suppressed 0 error(s) and cancelled 1 task(s). Shutdown was NOT clean; re-run with EZMSG_STRICT_SHUTDOWN=1 to debug tasks with poor shutdown behavior.
Process DefaultBackendProcess-5:
Process DefaultBackendProcess-2:
2026-03-17 11:09:37.902 - pid: 25309 - MainThread - WARNING - new_threaded_event_loop: Shutdown suppressed 0 error(s) and cancelled 4 task(s). Shutdown was NOT clean; re-run with EZMSG_STRICT_SHUTDOWN=1 to debug tasks with poor shutdown behavior.
Process DefaultBackendProcess-3:
Traceback (most recent call last):
Traceback (most recent call last):
Traceback (most recent call last):
Traceback (most recent call last):
  File "/Users/milsagw1/.local/share/uv/python/cpython-3.14.0rc1-macos-aarch64-none/lib/python3.14/multiprocessing/process.py", line 320, in _bootstrap
    self.run()
    ~~~~~~~~^^
  File "/Users/milsagw1/.local/share/uv/python/cpython-3.14.0rc1-macos-aarch64-none/lib/python3.14/multiprocessing/process.py", line 320, in _bootstrap
    self.run()
    ~~~~~~~~^^
  File "/Users/milsagw1/repos/ezmsg/src/ezmsg/core/backendprocess.py", line 208, in run
    self.process(loop)
    ~~~~~~~~~~~~^^^^^^
  File "/Users/milsagw1/repos/ezmsg/src/ezmsg/core/backendprocess.py", line 208, in run
    self.process(loop)
    ~~~~~~~~~~~~^^^^^^
  File "/Users/milsagw1/repos/ezmsg/src/ezmsg/core/backendprocess.py", line 564, in process
    loop.run_in_executor(None, self.monitor_termination, complete_tasks, loop)
    ~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/milsagw1/repos/ezmsg/src/ezmsg/core/backendprocess.py", line 564, in process
    loop.run_in_executor(None, self.monitor_termination, complete_tasks, loop)
    ~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/milsagw1/.local/share/uv/python/cpython-3.14.0rc1-macos-aarch64-none/lib/python3.14/asyncio/base_events.py", line 898, in run_in_executor
    executor.submit(func, *args), loop=self)
    ~~~~~~~~~~~~~~~^^^^^^^^^^^^^
  File "/Users/milsagw1/.local/share/uv/python/cpython-3.14.0rc1-macos-aarch64-none/lib/python3.14/asyncio/base_events.py", line 898, in run_in_executor
    executor.submit(func, *args), loop=self)
    ~~~~~~~~~~~~~~~^^^^^^^^^^^^^
  File "/Users/milsagw1/repos/ezmsg/src/ezmsg/core/backendprocess.py", line 105, in submit
    fut = super().submit(fn, *args, **kwargs)
  File "/Users/milsagw1/.local/share/uv/python/cpython-3.14.0rc1-macos-aarch64-none/lib/python3.14/multiprocessing/process.py", line 320, in _bootstrap
    self.run()
    ~~~~~~~~^^
  File "/Users/milsagw1/.local/share/uv/python/cpython-3.14.0rc1-macos-aarch64-none/lib/python3.14/concurrent/futures/thread.py", line 215, in submit
    self._adjust_thread_count()
    ~~~~~~~~~~~~~~~~~~~~~~~~~^^
  File "/Users/  File "/Users/milsagw1/.local/share/uv/python/cpython-3.14.0rc1-macos-aarch64-none/lib/python3.14/multiprocessing/process.py", line 320, in _bootstrap
    self.run()
    ~~~~~~~~^^
milsagw1/repos/ezmsg/src/ezmsg/core/backendprocess.py", line 105, in submit
    fut = super().submit(fn, *args, **kwargs)
  File "/Users/milsagw1/repos/ezmsg/src/ezmsg/core/backendprocess.py", line 96, in _adjust_thread_count
    self._initializer,
    ^^^^^^^^^^^^^^^^^
  File "/Users/milsagw1/repos/ezmsg/src/ezmsg/core/backendprocess.py", line 208, in run
    self.process(loop)
    ~~~~~~~~~~~~^^^^^^
  File "/Users/milsagw1/repos/ezmsg/src/ezmsg/core/backendprocess.py", line 208, in run
    self.process(loop)
    ~~~~~~~~~~~~^^^^^^
  File "/Users/milsagw1/.local/share/uv/python/cpython-3.14.0rc1-macos-aarch64-none/lib/python3.14/concurrent/futures/thread.py", line 215, in submit
    self._adjust_thread_count()
    ~~~~~~~~~~~~~~~~~~~~~~~~~^^
  File "/Users/milsagw1/repos/ezmsg/src/ezmsg/core/backendprocess.py", line 564, in process
    loop.run_in_executor(None, self.monitor_termination, complete_tasks, loop)
    ~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/milsagw1/repos/ezmsg/src/ezmsg/core/backendprocess.py", line 564, in process
    loop.run_in_executor(None, self.monitor_termination, complete_tasks, loop)
    ~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AttributeError: '_DaemonThreadPoolExecutor' object has no attribute '_initializer'
  File "/Users/milsagw1/repos/ezmsg/src/ezmsg/core/backendprocess.py", line 96, in _adjust_thread_count
    self._initializer,
    ^^^^^^^^^^^^^^^^^
  File "/Users/milsagw1/.local/share/uv/python/cpython-3.14.0rc1-macos-aarch64-none/lib/python3.14/asyncio/base_events.py", line 898, in run_in_executor
    executor.submit(func, *args), loop=self)
    ~~~~~~~~~~~~~~~^^^^^^^^^^^^^
  File "/Users/milsagw1/.local/share/uv/python/cpython-3.14.0rc1-macos-aarch64-none/lib/python3.14/asyncio/base_events.py", line 898, in run_in_executor
    executor.submit(func, *args), loop=self)
    ~~~~~~~~~~~~~~~^^^^^^^^^^^^^
  File "/Users/milsagw1/repos/ezmsg/src/ezmsg/core/backendprocess.py", line 105, in submit
    fut = super().submit(fn, *args, **kwargs)
  File "/Users/milsagw1/repos/ezmsg/src/ezmsg/core/backendprocess.py", line 105, in submit
    fut = super().submit(fn, *args, **kwargs)
AttributeError: '_DaemonThreadPoolExecutor' object has no attribute '_initializer'
  File "/Users/milsagw1/.local/share/uv/python/cpython-3.14.0rc1-macos-aarch64-none/lib/python3.14/concurrent/futures/thread.py", line 215, in submit
    self._adjust_thread_count()
    ~~~~~~~~~~~~~~~~~~~~~~~~~^^
  File "/Users/milsagw1/.local/share/uv/python/cpython-3.14.0rc1-macos-aarch64-none/lib/python3.14/concurrent/futures/thread.py", line 215, in submit
    self._adjust_thread_count()
    ~~~~~~~~~~~~~~~~~~~~~~~~~^^
  File "/Users/milsagw1/repos/ezmsg/src/ezmsg/core/backendprocess.py", line 96, in _adjust_thread_count
    self._initializer,
    ^^^^^^^^^^^^^^^^^
  File "/Users/milsagw1/repos/ezmsg/src/ezmsg/core/backendprocess.py", line 96, in _adjust_thread_count
    self._initializer,
    ^^^^^^^^^^^^^^^^^
AttributeError: '_DaemonThreadPoolExecutor' object has no attribute '_initializer'
AttributeError: '_DaemonThreadPoolExecutor' object has no attribute '_initializer'
2026-03-17 11:09:37.923 - pid: 25306 - MainThread - WARNING - new_threaded_event_loop: Shutdown suppressed 0 error(s) and cancelled 2 task(s). Shutdown was NOT clean; re-run with EZMSG_STRICT_SHUTDOWN=1 to debug tasks with poor shutdown behavior.
Traceback (most recent call last):
  File "/Users/milsagw1/repos/ezmsg/examples/ezmsg_toy.py", line 193, in <module>
    ez.run(
    ~~~~~~^
        SYSTEM=system,
        ^^^^^^^^^^^^^^
    ...<3 lines>...
        ],
        ^^
    )
    ^
  File "/Users/milsagw1/repos/ezmsg/src/ezmsg/core/backend.py", line 979, in run
    runner.run_blocking()
    ~~~~~~~~~~~~~~~~~~~^^
  File "/Users/milsagw1/repos/ezmsg/src/ezmsg/core/backend.py", line 671, in run_blocking
    self._run_main_process()
    ~~~~~~~~~~~~~~~~~~~~~~^^
  File "/Users/milsagw1/repos/ezmsg/src/ezmsg/core/backend.py", line 775, in _run_main_process
    self._main_process.process(self._loop)
    ~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^
  File "/Users/milsagw1/repos/ezmsg/src/ezmsg/core/backendprocess.py", line 564, in process
    loop.run_in_executor(None, self.monitor_termination, complete_tasks, loop)
    ~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/milsagw1/.local/share/uv/python/cpython-3.14.0rc1-macos-aarch64-none/lib/python3.14/asyncio/base_events.py", line 898, in run_in_executor
    executor.submit(func, *args), loop=self)
    ~~~~~~~~~~~~~~~^^^^^^^^^^^^^
  File "/Users/milsagw1/repos/ezmsg/src/ezmsg/core/backendprocess.py", line 105, in submit
    fut = super().submit(fn, *args, **kwargs)
  File "/Users/milsagw1/.local/share/uv/python/cpython-3.14.0rc1-macos-aarch64-none/lib/python3.14/concurrent/futures/thread.py", line 215, in submit
    self._adjust_thread_count()
    ~~~~~~~~~~~~~~~~~~~~~~~~~^^
  File "/Users/milsagw1/repos/ezmsg/src/ezmsg/core/backendprocess.py", line 96, in _adjust_thread_count
    self._initializer,
    ^^^^^^^^^^^^^^^^^
AttributeError: '_DaemonThreadPoolExecutor' object has no attribute '_initializer'