/usr/lib/ruby/ is in thin 1.6.3-2build4.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/ruby/vendor_ruby/
/usr/lib/ruby/vendor_ruby/rack/
/usr/lib/ruby/vendor_ruby/rack/adapter/
/usr/lib/ruby/vendor_ruby/rack/adapter/rails.rb
/usr/lib/ruby/vendor_ruby/rack/adapter/loader.rb
/usr/lib/ruby/vendor_ruby/thin.rb
/usr/lib/ruby/vendor_ruby/thin/
/usr/lib/ruby/vendor_ruby/thin/backends/
/usr/lib/ruby/vendor_ruby/thin/backends/base.rb
/usr/lib/ruby/vendor_ruby/thin/backends/swiftiply_client.rb
/usr/lib/ruby/vendor_ruby/thin/backends/tcp_server.rb
/usr/lib/ruby/vendor_ruby/thin/backends/unix_server.rb
/usr/lib/ruby/vendor_ruby/thin/daemonizing.rb
/usr/lib/ruby/vendor_ruby/thin/command.rb
/usr/lib/ruby/vendor_ruby/thin/server.rb
/usr/lib/ruby/vendor_ruby/thin/request.rb
/usr/lib/ruby/vendor_ruby/thin/controllers/
/usr/lib/ruby/vendor_ruby/thin/controllers/controller.rb
/usr/lib/ruby/vendor_ruby/thin/controllers/service.sh.erb
/usr/lib/ruby/vendor_ruby/thin/controllers/service.rb
/usr/lib/ruby/vendor_ruby/thin/controllers/cluster.rb
/usr/lib/ruby/vendor_ruby/thin/statuses.rb
/usr/lib/ruby/vendor_ruby/thin/stats.rb
/usr/lib/ruby/vendor_ruby/thin/stats.html.erb
/usr/lib/ruby/vendor_ruby/thin/connection.rb
/usr/lib/ruby/vendor_ruby/thin/headers.rb
/usr/lib/ruby/vendor_ruby/thin/logging.rb
/usr/lib/ruby/vendor_ruby/thin/version.rb
/usr/lib/ruby/vendor_ruby/thin/runner.rb
/usr/lib/ruby/vendor_ruby/thin/response.rb