/usr/lib/ruby/ is in ruby-rails-i18n 4.0.8-1.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/ruby/vendor_ruby/
/usr/lib/ruby/vendor_ruby/rails_i18n.rb
/usr/lib/ruby/vendor_ruby/rails-i18n.rb
/usr/lib/ruby/vendor_ruby/rails_i18n/
/usr/lib/ruby/vendor_ruby/rails_i18n/unicode.rb
/usr/lib/ruby/vendor_ruby/rails_i18n/common_pluralizations/
/usr/lib/ruby/vendor_ruby/rails_i18n/common_pluralizations/one_two_other.rb
/usr/lib/ruby/vendor_ruby/rails_i18n/common_pluralizations/other.rb
/usr/lib/ruby/vendor_ruby/rails_i18n/common_pluralizations/east_slavic.rb
/usr/lib/ruby/vendor_ruby/rails_i18n/common_pluralizations/romanian.rb
/usr/lib/ruby/vendor_ruby/rails_i18n/common_pluralizations/one_other.rb
/usr/lib/ruby/vendor_ruby/rails_i18n/common_pluralizations/one_upto_two_other.rb
/usr/lib/ruby/vendor_ruby/rails_i18n/common_pluralizations/west_slavic.rb
/usr/lib/ruby/vendor_ruby/rails_i18n/common_pluralizations/one_with_zero_other.rb
/usr/lib/ruby/vendor_ruby/rails_i18n/railtie.rb