Heads up: infrastructure requirements change coming: MQTT server version upgrade from v3 to v5 (reactive branch only, master is unaffected)

[Vadim Tkachenko]

Hello lurkers,

HCC code is currently using the HiveMQ MQTT v3 client library.
Upgrading it to MQTT v5 client will add a lot of nice things, but will
also most likely break the ability to use a MQTT v3 server.

ACTION ITEMS

If you're using the HCC master branch, there's no need to do anything.
Otherwise:

At the very least, you will need to upgrade just the server (if you're
using Mosquitto on Raspberry Pi that'll be from 1.5.7 to 2.0.11,
you'll need to enable anonymous access if you're using it, and specify
listener interfaces).

For me, it was simpler to upgrade the whole OS (from "Raspbian
GNU/Linux 10 (buster)" to "Debian GNU/Linux 11 (bullseye)"I was able
to do that seamlessly in place several times, don't remember any
pitfalls).

No rush, just keep this in mind :)

--vt