/usr/lib/ruby/vendor_ruby/ is in ruby-grape-logging 1.3.0-1.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/ruby/vendor_ruby/grape_logging/
/usr/lib/ruby/vendor_ruby/grape_logging/formatters/
/usr/lib/ruby/vendor_ruby/grape_logging/formatters/default.rb
/usr/lib/ruby/vendor_ruby/grape_logging/formatters/json.rb
/usr/lib/ruby/vendor_ruby/grape_logging/loggers/
/usr/lib/ruby/vendor_ruby/grape_logging/loggers/base.rb
/usr/lib/ruby/vendor_ruby/grape_logging/loggers/client_env.rb
/usr/lib/ruby/vendor_ruby/grape_logging/loggers/filter_parameters.rb
/usr/lib/ruby/vendor_ruby/grape_logging/loggers/request_headers.rb
/usr/lib/ruby/vendor_ruby/grape_logging/loggers/response.rb
/usr/lib/ruby/vendor_ruby/grape_logging/middleware/
/usr/lib/ruby/vendor_ruby/grape_logging/middleware/request_logger.rb
/usr/lib/ruby/vendor_ruby/grape_logging/multi_io.rb
/usr/lib/ruby/vendor_ruby/grape_logging/reporters/
/usr/lib/ruby/vendor_ruby/grape_logging/reporters/active_support_reporter.rb
/usr/lib/ruby/vendor_ruby/grape_logging/reporters/logger_reporter.rb
/usr/lib/ruby/vendor_ruby/grape_logging/timings.rb
/usr/lib/ruby/vendor_ruby/grape_logging/version.rb
/usr/lib/ruby/vendor_ruby/grape_logging.rb