Bug report

Bug description:

async def agen():
    return
    yield


try:
    athrow = agen().athrow()
    athrow.close()
except TypeError:
    print("good")
else:
    print("bad")

output:

bad

CPython versions tested on:

3.8, 3.9, 3.10, 3.11, 3.12, 3.13, CPython main branch

Operating systems tested on:

Linux

Linked PRs

• gh-117852: eagerly check arguments to asyncgen.athrow() #134868