/usr/lib/ruby/ is in ruby-jar-dependencies 0.3.10-2.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/ruby/vendor_ruby/
/usr/lib/ruby/vendor_ruby/jar-dependencies.rb
/usr/lib/ruby/vendor_ruby/jar_dependencies.rb
/usr/lib/ruby/vendor_ruby/jar_install_post_install_hook.rb
/usr/lib/ruby/vendor_ruby/jar_installer.rb
/usr/lib/ruby/vendor_ruby/jars/
/usr/lib/ruby/vendor_ruby/jars/attach_jars_pom.rb
/usr/lib/ruby/vendor_ruby/jars/classpath.rb
/usr/lib/ruby/vendor_ruby/jars/gemspec_artifacts.rb
/usr/lib/ruby/vendor_ruby/jars/gemspec_pom.rb
/usr/lib/ruby/vendor_ruby/jars/installer.rb
/usr/lib/ruby/vendor_ruby/jars/lock.rb
/usr/lib/ruby/vendor_ruby/jars/lock_down.rb
/usr/lib/ruby/vendor_ruby/jars/lock_down_pom.rb
/usr/lib/ruby/vendor_ruby/jars/maven_exec.rb
/usr/lib/ruby/vendor_ruby/jars/maven_factory.rb
/usr/lib/ruby/vendor_ruby/jars/maven_settings.rb
/usr/lib/ruby/vendor_ruby/jars/output_jars_pom.rb
/usr/lib/ruby/vendor_ruby/jars/post_install_hook.rb
/usr/lib/ruby/vendor_ruby/jars/settings.xml
/usr/lib/ruby/vendor_ruby/jars/setup.rb
/usr/lib/ruby/vendor_ruby/jars/version.rb