Install ruby-librdf by entering the following commands in the terminal:
sudo apt update sudo apt install ruby-librdf
Description:
Ruby language bindings for the Redland RDF library
This package contains the files needed to use the Redland Resource Description Framework (RDF) library in Ruby programs.
Homepage: http://librdf.org/docs/ruby.html
Version: 1.0.17.1+dfsg-1.3build4
Section: universe/ruby