I was in the process of eyeballing the docs and fixing things when I came upon a :ref: that steadfastly refused to resolve:

:class:`asyncio.StreamReaderProtocol`

After hunting around, apparently that class was last documented in Python 3.6: https://docs.python.org/3.6/library/asyncio-stream.html#streamreaderprotocol

It's gone since Python 3.7, that's why the :ref: won't resolve.

Digging deeper, I found bpo-37639 with comment from @asvetlov (I'm assuming the same person, apologies if not):

We are striving to remove it from public API step by step: documentation-deprecation-removal.

If you really need the class -- please copy-paste the source lines into your project and use the copy on your own.

So, will we stop inheriting from that class and as suggested, just copy-and-paste the source lines?

I fear that one day things will blow up if this class's definition got removed and/or remade... which is why I'm adding the [tech-debt] label there.