/usr/lib/ is in ruby-multi-json 1.8.0-1.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/ruby/
/usr/lib/ruby/vendor_ruby/
/usr/lib/ruby/vendor_ruby/multi_json/
/usr/lib/ruby/vendor_ruby/multi_json/options.rb
/usr/lib/ruby/vendor_ruby/multi_json/vendor/
/usr/lib/ruby/vendor_ruby/multi_json/vendor/okjson.rb
/usr/lib/ruby/vendor_ruby/multi_json/convertible_hash_keys.rb
/usr/lib/ruby/vendor_ruby/multi_json/version.rb
/usr/lib/ruby/vendor_ruby/multi_json/load_error.rb
/usr/lib/ruby/vendor_ruby/multi_json/adapter.rb
/usr/lib/ruby/vendor_ruby/multi_json/adapters/
/usr/lib/ruby/vendor_ruby/multi_json/adapters/gson.rb
/usr/lib/ruby/vendor_ruby/multi_json/adapters/jr_jackson.rb
/usr/lib/ruby/vendor_ruby/multi_json/adapters/ok_json.rb
/usr/lib/ruby/vendor_ruby/multi_json/adapters/json_pure.rb
/usr/lib/ruby/vendor_ruby/multi_json/adapters/yajl.rb
/usr/lib/ruby/vendor_ruby/multi_json/adapters/oj.rb
/usr/lib/ruby/vendor_ruby/multi_json/adapters/json_gem.rb
/usr/lib/ruby/vendor_ruby/multi_json/adapters/json_common.rb
/usr/lib/ruby/vendor_ruby/multi_json/adapters/nsjsonserialization.rb
/usr/lib/ruby/vendor_ruby/multi_json.rb