Install gir1.2-retro-0.14 by entering the following commands in the terminal:
sudo apt update sudo apt install gir1.2-retro-0.14
Description:
GObject introspection data for retro-gtk
This package contains GObject introspection information. . It can be used by packages using the GIRepository format to generate dynamic bindings.
Homepage: https://wiki.gnome.org/Apps/Games
Version: 0.14.0-1
Section: universe/introspection