I’ve upgraded to 20.03 (on this particular machine from 18.03, but I’m running another machine with the same configuration on 19.09 without problems). This worked fine on both of the previous systems.
I’m running an xmonad configuration inside a VirtualBox.
My guest system does not adapt in size when I either resize the window it’s running in or go full screen. On top of that, it seems that the windows inside the guest system “think” that they have more screen space than I’m able to see, that is: part these windows are cropped out of view for me.
Regarding the guest extensions, I have all of the following in my configuration.nix:
nixpkgs.config.allowUnfree = true;
virtualisation.virtualbox.host.enable = true;
virtualisation.virtualbox.host.enableExtensionPack = true;
What would be the best place to start debugging the issue?