Adapt task spawning to AnyIO 4.14 typing

Author: Kludex

src/mcp/shared/jsonrpc_dispatcher.py

@@ -680,10 +680,14 @@ def _spawn(
         message; `Context.run` makes the spawned handler inherit that context.
         """
         assert self._tg is not None
+
+        async def run() -> None:
+            await fn(*args)
+
         if sender_ctx is not None:
-            sender_ctx.run(self._tg.start_soon, fn, *args)
+            sender_ctx.run(self._tg.start_soon, run)
         else:
-            self._tg.start_soon(fn, *args)
+            self._tg.start_soon(run)
 
     def _fan_out_closed(self) -> None:
         """Wake every pending `send_raw_request` waiter with `CONNECTION_CLOSED`.

tests/client/test_stdio.py

@@ -444,7 +444,10 @@ async def die_late() -> None:
                     process.exit(0)
 
                 # The grace wait starts when stdin closes; anchor the death there.
-                process.on_stdin_close = lambda: tg.start_soon(die_late)
+                def schedule_death() -> None:
+                    tg.start_soon(die_late)
+
+                process.on_stdin_close = schedule_death
                 # no branch: the tracer drops this nested async-with's arcs under
                 # trio's MockClock even though the body runs.
                 async with stdio_client(FAKE_PARAMS):  # pragma: no branch