Aiohttp: Aiohttp.web unsupported for 3.8

Long story short

Aiohttp.web servers on 3.8 appear to refuse all requests. Tested with 3.7 and it works fine.

Expected behaviour

For it to handle requests normally.

Actual behaviour

The server doesn't even receive the request, and the client returns with a ServerDisconnectedError

Steps to reproduce

from aiohttp import web


routes = web.RouteTableDef()


@routes.get("/")
async def hello(request):
    return web.Response(text="Hi!")


app = web.Application()
app.add_routes(routes)
web.run_app(app)

Your environment