`sleep()` hangs indefinitely when using a custom clock

Tested on 0.32 and the current `master`. MRE: ```py import trio import trio.testing class FooMockClock(trio.abc.Clock): def __init__(self) -> None: self._clock = trio.testing.MockClock(autojump_threshold=0) def current_time(self) -> float: return self._clock.current_time() def deadline_to_sleep_time(self, deadline: float) -> float: return self._clock.deadline_to_sleep_time(deadline) def start_clock(self) -> None: self._clock.start_clock() async def main(): print(trio.current_time()) await trio.sleep(2) print(trio.current_time()) if __name__ == '__main__': print("MockClock") trio.run(main, clock=trio.testing.MockClock(autojump_threshold=0)) print("FooMockClock") trio.run(main, clock=FooMockClock()) ``` Output: ``` MockClock 0.0 2.0 FooMockClock 0.0 < hangs indefinitely > ``` I expected the second `run()` to behave exactly the same as the first. What am I doing wrong? Also, if I copy-paste `trio.testing.MockClock` verbatim to this script and use that, the execution crashes - may be related: ``` Traceback (most recent call last): File "/Users/bogdan/wb/repos/trio/src/trio/_core/_run.py", line 2813, in unrolled_run assert isinstance(runner.clock, _core.MockClock) AssertionError The above exception was the direct cause of the following exception: Traceback (most recent call last): File "/Users/bogdan/wb/github/nucypher-async/t_new.py", line 185, in <module> trio.run(main, clock=MockClock(autojump_threshold=0)) File "/Users/bogdan/wb/repos/trio/src/trio/_core/_run.py", line 2538, in run timeout = gen.send(next_send) File "/Users/bogdan/wb/repos/trio/src/trio/_core/_run.py", line 2951, in unrolled_run raise TrioInternalError("internal error in Trio - please file a bug!") from exc trio.TrioInternalError: internal error in Trio - please file a bug! Exception ignored in: <coroutine object Runner.init at 0x106a26500> Traceback (most recent call last): File "/Users/bogdan/wb/repos/trio/src/trio/_core/_run.py", line 2156, in init File "/Users/bogdan/wb/repos/trio/src/trio/_core/_run.py", line 1112, in __aexit__ File "/Users/bogdan/wb/repos/trio/src/trio/_core/_run.py", line 1288, in _nested_child_finished File "/Users/bogdan/wb/repos/trio/src/trio/_core/_run.py", line 1252, in _add_exc File "/Users/bogdan/wb/repos/trio/src/trio/_core/_run.py", line 933, in _cancel File "/Users/bogdan/wb/repos/trio/src/trio/_core/_run.py", line 501, in recalculate File "/Users/bogdan/wb/repos/trio/src/trio/_core/_run.py", line 1671, in _attempt_delivery_of_any_pending_cancel File "/Users/bogdan/wb/repos/trio/src/trio/_core/_run.py", line 1644, in _attempt_abort File "/Users/bogdan/wb/repos/trio/src/trio/_core/_io_kqueue.py", line 162, in abort File "/Users/bogdan/wb/repos/trio/src/trio/_core/_io_kqueue.py", line 184, in abort ValueError: I/O operation on closed kqueue object Exception ignored in: <function Nursery.__del__ at 0x105b208b0> Traceback (most recent call last): File "/Users/bogdan/wb/repos/trio/src/trio/_core/_run.py", line 1486, in __del__ AssertionError: Exception ignored in: <coroutine object main at 0x106a26570> Traceback (most recent call last): File "/Users/bogdan/wb/github/nucypher-async/t_new.py", line 180, in main File "/Users/bogdan/wb/repos/trio/src/trio/_timeouts.py", line 111, in sleep File "/Users/bogdan/wb/repos/trio/src/trio/_timeouts.py", line 91, in sleep_until File "/Users/bogdan/wb/repos/trio/src/trio/_core/_run.py", line 714, in __exit__ File "/Users/bogdan/wb/repos/trio/src/trio/_core/_run.py", line 640, in _close File "/Users/bogdan/wb/repos/trio/src/trio/_core/_run.py", line 2993, in current_task RuntimeError: must be called from async context Exception ignored in: <function Nursery.__del__ at 0x105b208b0> Traceback (most recent call last): File "/Users/bogdan/wb/repos/trio/src/trio/_core/_run.py", line 1486, in __del__ AssertionError: bogdan@lair ~/w/g/nucypher-async (todo-party) [1]> python t_new.py 0.0 Traceback (most recent call last): File "/Users/bogdan/wb/repos/trio/src/trio/_core/_run.py", line 2813, in unrolled_run assert isinstance(runner.clock, _core.MockClock) AssertionError The above exception was the direct cause of the following exception: Traceback (most recent call last): File "/Users/bogdan/wb/github/nucypher-async/t_new.py", line 186, in <module> trio.run(main, clock=MockClock(autojump_threshold=0)) File "/Users/bogdan/wb/repos/trio/src/trio/_core/_run.py", line 2538, in run timeout = gen.send(next_send) File "/Users/bogdan/wb/repos/trio/src/trio/_core/_run.py", line 2951, in unrolled_run raise TrioInternalError("internal error in Trio - please file a bug!") from exc trio.TrioInternalError: internal error in Trio - please file a bug! Exception ignored in: <coroutine object Runner.init at 0x106ade500> Traceback (most recent call last): File "/Users/bogdan/wb/repos/trio/src/trio/_core/_run.py", line 2156, in init File "/Users/bogdan/wb/repos/trio/src/trio/_core/_run.py", line 1112, in __aexit__ File "/Users/bogdan/wb/repos/trio/src/trio/_core/_run.py", line 1288, in _nested_child_finished File "/Users/bogdan/wb/repos/trio/src/trio/_core/_run.py", line 1252, in _add_exc File "/Users/bogdan/wb/repos/trio/src/trio/_core/_run.py", line 933, in _cancel File "/Users/bogdan/wb/repos/trio/src/trio/_core/_run.py", line 501, in recalculate File "/Users/bogdan/wb/repos/trio/src/trio/_core/_run.py", line 1671, in _attempt_delivery_of_any_pending_cancel File "/Users/bogdan/wb/repos/trio/src/trio/_core/_run.py", line 1644, in _attempt_abort File "/Users/bogdan/wb/repos/trio/src/trio/_core/_io_kqueue.py", line 162, in abort File "/Users/bogdan/wb/repos/trio/src/trio/_core/_io_kqueue.py", line 184, in abort ValueError: I/O operation on closed kqueue object Exception ignored in: <function Nursery.__del__ at 0x105bd8820> Traceback (most recent call last): File "/Users/bogdan/wb/repos/trio/src/trio/_core/_run.py", line 1486, in __del__ AssertionError: Exception ignored in: <coroutine object main at 0x106ade570> Traceback (most recent call last): File "/Users/bogdan/wb/github/nucypher-async/t_new.py", line 181, in main File "/Users/bogdan/wb/repos/trio/src/trio/_timeouts.py", line 111, in sleep File "/Users/bogdan/wb/repos/trio/src/trio/_timeouts.py", line 91, in sleep_until File "/Users/bogdan/wb/repos/trio/src/trio/_core/_run.py", line 714, in __exit__ File "/Users/bogdan/wb/repos/trio/src/trio/_core/_run.py", line 640, in _close File "/Users/bogdan/wb/repos/trio/src/trio/_core/_run.py", line 2993, in current_task RuntimeError: must be called from async context Exception ignored in: <function Nursery.__del__ at 0x105bd8820> Traceback (most recent call last): File "/Users/bogdan/wb/repos/trio/src/trio/_core/_run.py", line 1486, in __del__ AssertionError: ```