Linux Mint 21 Vanessa on main laptop

I used the GUI tool:

• sudo apt update
• sudo apt install mintupgrade
• sudo mintupgrade
  

This tool required/proposed to start a timeshift snapshot before upgrading.  I did create that configuration to store the snapshots on /media/luc/Sea1/timeshift/

Then it took quite a while to simulate/download/perform the upgrade.  It also removed some "non official" packages like the Belgian EID stuff and maybe some other Debian or Ubuntu packages (I don't remember which ones).  But finally ended OK and reboot was fine (no need to reinstall Grub or anything like that).

UrBackup agent still alive and kicking.  Darktable version unchanged (3.6.0).  Multi-head monitor configuration still OK.