/usr/lib/ruby/vendor_ruby/ is in ruby-amqp 0.9.5-2.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/ruby/vendor_ruby/amqp/
/usr/lib/ruby/vendor_ruby/amqp.rb
/usr/lib/ruby/vendor_ruby/amqp/bit_set.rb
/usr/lib/ruby/vendor_ruby/amqp/broker.rb
/usr/lib/ruby/vendor_ruby/amqp/channel.rb
/usr/lib/ruby/vendor_ruby/amqp/client.rb
/usr/lib/ruby/vendor_ruby/amqp/compatibility/
/usr/lib/ruby/vendor_ruby/amqp/compatibility/ruby187_patchlevel_check.rb
/usr/lib/ruby/vendor_ruby/amqp/connection.rb
/usr/lib/ruby/vendor_ruby/amqp/consumer.rb
/usr/lib/ruby/vendor_ruby/amqp/deprecated/
/usr/lib/ruby/vendor_ruby/amqp/deprecated/fork.rb
/usr/lib/ruby/vendor_ruby/amqp/deprecated/logger.rb
/usr/lib/ruby/vendor_ruby/amqp/deprecated/mq.rb
/usr/lib/ruby/vendor_ruby/amqp/deprecated/rpc.rb
/usr/lib/ruby/vendor_ruby/amqp/exceptions.rb
/usr/lib/ruby/vendor_ruby/amqp/exchange.rb
/usr/lib/ruby/vendor_ruby/amqp/ext/
/usr/lib/ruby/vendor_ruby/amqp/ext/em.rb
/usr/lib/ruby/vendor_ruby/amqp/ext/emfork.rb
/usr/lib/ruby/vendor_ruby/amqp/extensions/
/usr/lib/ruby/vendor_ruby/amqp/extensions/rabbitmq.rb
/usr/lib/ruby/vendor_ruby/amqp/header.rb
/usr/lib/ruby/vendor_ruby/amqp/int_allocator.rb
/usr/lib/ruby/vendor_ruby/amqp/integration/
/usr/lib/ruby/vendor_ruby/amqp/integration/rails.rb
/usr/lib/ruby/vendor_ruby/amqp/logger.rb
/usr/lib/ruby/vendor_ruby/amqp/queue.rb
/usr/lib/ruby/vendor_ruby/amqp/rpc.rb
/usr/lib/ruby/vendor_ruby/amqp/session.rb
/usr/lib/ruby/vendor_ruby/amqp/utilities/
/usr/lib/ruby/vendor_ruby/amqp/utilities/event_loop_helper.rb
/usr/lib/ruby/vendor_ruby/amqp/utilities/server_type.rb
/usr/lib/ruby/vendor_ruby/amqp/version.rb
/usr/lib/ruby/vendor_ruby/mq/
/usr/lib/ruby/vendor_ruby/mq.rb
/usr/lib/ruby/vendor_ruby/mq/logger.rb
/usr/lib/ruby/vendor_ruby/mq/rpc.rb