CI run against Twisted trunk is failing

[github-actions]

See https://github.com/matrix-org/synapse/actions/runs/1290148067

[DMRobertson]

Need to see if this was a one-off or consistent failure.

[clokep]

synapse/replication/tcp/redis.py:367: error: Argument 1 to "connectTCP" of "IReactorTCP" has incompatible type "bytes"; expected "str"  [arg-type]

This is due to twisted/twisted#1664

[richvdh]

(we need to update our call to connectTCP to pass a str where we are currently passing a bytes)

[DMRobertson]

Looks to be just a case of not calling .encode(). But I'm not sure how to make mypy happy with older and newer versions of twisted. I guess we only run mypy in the 3.9 tox environment?

[richvdh]

But I'm not sure how to make mypy happy with older and newer versions of twisted

honestly, I suspect you'll need a # type: ignore until the next release of twisted.

[richvdh]

(which is what we do elsewhere we call connectTCP - synapse/handlers/send_email.py for example)

[DMRobertson]

Indeed---beat me to it!