/usr/lib/ is in ruby-redis-store 1.3.0-3.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/ruby/
/usr/lib/ruby/vendor_ruby/
/usr/lib/ruby/vendor_ruby/redis/
/usr/lib/ruby/vendor_ruby/redis/distributed_store.rb
/usr/lib/ruby/vendor_ruby/redis/store/
/usr/lib/ruby/vendor_ruby/redis/store/factory.rb
/usr/lib/ruby/vendor_ruby/redis/store/interface.rb
/usr/lib/ruby/vendor_ruby/redis/store/namespace.rb
/usr/lib/ruby/vendor_ruby/redis/store/redis_version.rb
/usr/lib/ruby/vendor_ruby/redis/store/serialization.rb
/usr/lib/ruby/vendor_ruby/redis/store/ttl.rb
/usr/lib/ruby/vendor_ruby/redis/store/version.rb
/usr/lib/ruby/vendor_ruby/redis/store.rb
/usr/lib/ruby/vendor_ruby/redis-store.rb