I can't install gnome-shell on Ubuntu 17.04. What am I missing?
ยป sudo apt install gnome-shell
Reading package lists... Done
Building dependency tree
Reading state information... Done
Package gnome-shell is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source
E: Package 'gnome-shell' has no installation candidate