demo.py

import asyncio
import contextlib

async def child(sock):
    try:
        with contextlib.closing(sock):
            await asyncio.sleep(2)
    except Exception as e:
        print(f"child task got error: {type(e)=} {e=}")
        raise

class Sock:
    async def aclose(self):
        await asyncio.sleep(1)

async def main():
    try:
        sock = Sock()
        async with asyncio.timeout(1):
            async with asyncio.TaskGroup() as tg:
                # Make two concurrent calls to child()
                tg.create_task(child(Sock()))
                tg.create_task(child(Sock()))
                async with contextlib.aclosing(sock):
                    await asyncio.sleep(2)
    except* AttributeError:
        print("handled value error")


asyncio.run(main())

Please file a CPython issue for this.