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:
A couple of things might come together, one of it is that the currently available VBoxCLient 6.1.6 in nixpkgs is buggy and simply can’t do the resizing anymore.
Some more community effort is also trying to create a workaround by using another graphicsdriver which hasn’t been merged the last time I checked. That one also comes with reconfiguring your machines graphicsadapter as far as I understood (VMSVGA instead of VBOXVGA or something).
