try asyncio.run again

src/trio/_core/_tests/test_guest_mode.py

@@ -438,9 +438,9 @@ def aiotrio_run(
     pass_not_threadsafe: bool = True,
     **start_guest_run_kwargs: Any,
 ) -> T:
-    loop = asyncio.new_event_loop()
 
     async def aio_main() -> T:
+        loop = asyncio.get_running_loop()
         trio_done_fut: asyncio.Future[Outcome[T]] = loop.create_future()
 
         def trio_done_callback(main_outcome: Outcome[T]) -> None:
@@ -459,12 +459,7 @@ def trio_done_callback(main_outcome: Outcome[T]) -> None:
 
         return (await trio_done_fut).unwrap()
 
-    try:
-        # can't use asyncio.run because that fails on Windows (3.8, x64, with
-        # Komodia LSP)
-        return loop.run_until_complete(aio_main())
-    finally:
-        loop.close()
+    return asyncio.run(aio_main())
 
 
 def test_guest_mode_on_asyncio() -> None: