Debian 11 was released on 2021-08-15, yay!
So I set out to "dist-upgrade" my systems. Of course, there were some surprises involved!
On the only 7x24 system (pc-engines APU) a MQTT broker is running. Upgrading the system changed it from version 1.6 to 2.0. I'm not sure, whether this was mentioned in the list of important changes. But a problem was showing itself quite soon: the collection of environmental data from my microcontrollers ceased for a specific group. Turned out, that the collector program was unable to deliver its data to said MQTT broker.
Connection refused.
Reading the man page revealed, that I now need to explicitly allow the listener of mosquitto on all interfaces/networks, which I care about. Otherwise only localhost is served.
On the same system I had updated nextcloud to the latest stable revision a few days before the dist-upgrade to Debian 11. After the upgrade of Debian it ceased to work.
Bad Gateway.
I found that one quickly: in the nginx configuration I had to adjust the information about the php-fpm socket. The version had changed from 7.3 to 7.4.
fastcgi_pass unix:/run/php/php7.4-fpm.sock;
After that the error message at least changed:
Internal server error. Please contact your systems administrator.
Aha. That admin is me. So I contacted myself to spread the news, and then went to bed. Nextcloud is not the most used service on this system.
The next day I looked at it again. And after installing new versions of several php packages, the error disappeared. --- While this service is not important, it would have caused some grief nonetheless.
On my workstation, typesetting the Forth magazine (Vierte Dimension) ceased to work.
! Undefined control sequence.
\set@color ...\@pdfcolorstack push{\current@color
}\aftergroup \reset@color
The editor in charge set up a docker image with an old version of texlive. Problem solved. But we have not yet found out, what exactly is causing this.
In my opinion my workstation is a fairly big beast with approximately 2800 packages installed (remember: no desktop GUI other than i3-wm). So some breakage is to be expected. The complexity of all these things working together is at least considerable. That being said, I find it very respectable, that only 3 things broke for me, given the long list of installed packages. Of course, zero breaks would have been nicer. But I did not spend extraordinary amounts of time.
So, thanks to all people contributing to free software in general and Debian and its upstreams inparticular!
Cheers,
~ew