/usr/lib/ruby/vendor_ruby/ is in ruby-clutter 2.2.5-4build1.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/ruby/vendor_ruby/clutter/
/usr/lib/ruby/vendor_ruby/clutter.rb
/usr/lib/ruby/vendor_ruby/clutter/actor-iter.rb
/usr/lib/ruby/vendor_ruby/clutter/actor.rb
/usr/lib/ruby/vendor_ruby/clutter/animatable.rb
/usr/lib/ruby/vendor_ruby/clutter/brightness-contrast-effect.rb
/usr/lib/ruby/vendor_ruby/clutter/cairo.rb
/usr/lib/ruby/vendor_ruby/clutter/clutter.rb
/usr/lib/ruby/vendor_ruby/clutter/color.rb
/usr/lib/ruby/vendor_ruby/clutter/event.rb
/usr/lib/ruby/vendor_ruby/clutter/point.rb
/usr/lib/ruby/vendor_ruby/clutter/text-buffer.rb
/usr/lib/ruby/vendor_ruby/clutter/text.rb
/usr/lib/ruby/vendor_ruby/clutter/threads.rb