Attempt to sudo apt upgrade a Nested Container hangs

I created an LXD Ubuntu 22.04 container CN1 and enable Nesting.
In CN1 I created another LXD container named SUBCN1.

After exec’ing into SUBCN1 I executed:

# apt update && apt upgrade -h

The Update went ok but the Upgrade hung

Setting up libdbus-1-3:amd64 (1.12.16-2ubuntu2.3) …
Setting up dbus (1.12.16-2ubuntu2.3) …
A reboot is required to replace the running dbus-daemon.
Please reboot the system when convenient.
Setting up sosreport (4.4-1ubuntu0.20.04.1) …
Setting up libperl5.30:amd64 (5.30.0-9ubuntu0.3) …
Setting up libcurl4:amd64 (7.68.0-1ubuntu2.14) …
Setting up curl (7.68.0-1ubuntu2.14) …
Setting up ubuntu-advantage-tools (27.11.3~20.04.1) …
Installing new version of config file /etc/apt/apt.conf.d/20apt-esm-hook.conf …

The Upgrade command hangs trying to install ubuntu-advantage-tools?

I’ve tried this on both a privileged and a non-privileged container and both hang.

Anyone got any ideas why or what to look at?

Brian

This was due to my Mullvad VPN install that mounted net_cls (cgroup1) over cgroup2 2

This caused LXD containers to fail to start

The solution is at the end of this thread: