/usr/lib/ is in ruby-commandline 0.7.10-12.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/ruby/vendor_ruby/test/unit/
/usr/lib/ruby/
/usr/lib/ruby/vendor_ruby/
/usr/lib/ruby/vendor_ruby/test/
/usr/lib/ruby/vendor_ruby/test/unit/systemtest.rb
/usr/lib/ruby/vendor_ruby/commandline.rb
/usr/lib/ruby/vendor_ruby/commandline/
/usr/lib/ruby/vendor_ruby/commandline/utils.rb
/usr/lib/ruby/vendor_ruby/commandline/optionparser/
/usr/lib/ruby/vendor_ruby/commandline/optionparser/option.rb
/usr/lib/ruby/vendor_ruby/commandline/optionparser/optiondata.rb
/usr/lib/ruby/vendor_ruby/commandline/optionparser/optionparser.rb
/usr/lib/ruby/vendor_ruby/commandline/optionparser.rb
/usr/lib/ruby/vendor_ruby/commandline/application.rb
/usr/lib/ruby/vendor_ruby/commandline/kernel.rb