2-node-supercomputer.net 2020-07-04

Upgrading to Debian 11 (bullseye)

Debian 11, codename bullseye, is not yet released. However, you can already upgrade it while it is in testing.

In principle, the upgrade should be easy: simply update your /etc/apt/sources.list to contain

deb http://deb.debian.org/debian/ bullseye main contrib non-free
deb-src http://deb.debian.org/debian/ bullseye main contrib non-free

deb http://security.debian.org/debian-security bullseye-security main contrib non-free
deb-src http://security.debian.org/debian-security bullseye-security main contrib non-free

deb http://deb.debian.org/debian/ bullseye-updates main contrib non-free
deb-src http://deb.debian.org/debian/ bullseye-updates main contrib non-free

deb http://deb.debian.org/debian/ bullseye-backports main contrib non-free
deb-src http://deb.debian.org/debian/ bullseye-backports main contrib non-free

Then, run

$ sudo apt dist-upgrade

Of course, in practice you run into problems along the way. In my case, there was a dependency issue with libgcc-8-dev, which I tracked down (without too much due diligence, uh oh) to libmutter-3-0 being locally installed and not upgraded. So purge that and rerun the dist-upgrade. Done.

Not quite. It takes a long time, the timeout locked the screen, and it wouldn’t even let me enter the password anymore. Argh.

But not to despair, use ssh from another computer (or perhaps Alt+Ctrl+F2 to get a console?), and issue the following command:

$ sudo loginctl unlock-sessions

Voila, screen unlocked!