Getting a far more recent build of mosquitto (2.0.18 vs 2.0.11)

Wondering if I can use debian backports in my sources list to get the latest v 2.0.18 of mosquitto - there’s been quite a few revisions since the last official bookworm release - 2.0.11 ?

As far as I can see we use the official repo from mosquitto:
https://github.com/MichaIng/DietPi/blob/e87e1ddd6e525da2128b509ac11fc1ab01882297/dietpi/dietpi-software#L6680

So you could update with

apt update
apt install mosquitto

Yeah, sorry, I didn’t provide enough info - running on Pi Zero W (armhf packages).

So the note below where you link to says ‘Current builds are not ARMv6 compatible’

Debian -- Details of package mosquitto in bookworm - offers 2.0.11
Debian -- Details of package mosquitto in bookworm-backports - offers 2.0.18

For RPi Zero W (ARMv6), Raspbian is/needs to be used instead of Debian. And Raspbian has no backports repository. So for a more recent Mosquitto, one needs to do an own source build.

Their own APT repo supports ARMv7 and x86_64 only … ah, it does not help you, but I see just last month, for Bookworm, ARMv8/arm64 support has been added: Index of /debian/dists/bookworm/