$ sudo apt-get update
$ sudo apt-get install ruby-gobject-introspection-dbg

ruby-gobject-introspection-dbg is installed in your system.

Make ensure the ruby-gobject-introspection-dbg package were installed using the commands given below,

$ sudo dpkg-query -l | grep ruby-gobject-introspection-dbg*

You will get with ruby-gobject-introspection-dbg package name, version, architecture and description in a table

ruby-gobject-introspection-dbg package basic information: