Reading package lists... Done
Building dependency tree
Reading state information... Done
Package gir1.2-gtk-3.0 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

Package python3-xdg 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 'python3-xdg' has no installation candidate
E: Package 'gir1.2-gtk-3.0' has no installation candidate