/usr/lib/ruby/ is in ruby-patron 0.4.18-1.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/ruby/vendor_ruby/
/usr/lib/ruby/vendor_ruby/patron.rb
/usr/lib/ruby/vendor_ruby/patron/
/usr/lib/ruby/vendor_ruby/patron/session.rb
/usr/lib/ruby/vendor_ruby/patron/util.rb
/usr/lib/ruby/vendor_ruby/patron/proxy_type.rb
/usr/lib/ruby/vendor_ruby/patron/request.rb
/usr/lib/ruby/vendor_ruby/patron/error.rb
/usr/lib/ruby/vendor_ruby/patron/version.rb
/usr/lib/ruby/vendor_ruby/patron/response.rb
/usr/lib/ruby/vendor_ruby/1.9.1/
/usr/lib/ruby/vendor_ruby/1.9.1/x86_64-linux/
/usr/lib/ruby/vendor_ruby/1.9.1/x86_64-linux/patron/
/usr/lib/ruby/vendor_ruby/1.9.1/x86_64-linux/patron/session_ext.so