ubuntu

$ sudo apt install --reinstall ubuntu-desktop
Reading package lists... Done
Building dependency tree
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
 ubuntu-desktop : Depends: gdm3 but it is not going to be installed
                  Depends: gnome-shell but it is not going to be installed
                  Depends: gstreamer1.0-packagekit but it is not going to be installed
                  Depends: software-properties-gtk but it is not going to be installed
                  Recommends: brltty but it is not going to be installed
                  Recommends: gnome-disk-utility but it is not going to be installed
                  Recommends: gnome-initial-setup but it is not going to be installed
                  Recommends: gnome-software-plugin-snap but it is not going to be installed
                  Recommends: gvfs-fuse but it is not going to be installed
                  Recommends: hplip but it is not going to be installed
                  Recommends: libreoffice-writer but it is not going to be installed
                  Recommends: nautilus-share but it is not going to be installed
                  Recommends: network-manager-config-connectivity-ubuntu but it is not going to be installed
                  Recommends: network-manager-pptp-gnome but it is not going to be installed
                  Recommends: packagekit
                  Recommends: snapd but it is not going to be installed
                  Recommends: ubuntu-software but it is not going to be installed
                  Recommends: usb-creator-gtk but it is not going to be installed
E: Unable to correct problems, you have held broken packages.