/usr/lib/ruby/ is in ruby-treetop 1.6.3-1.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/ruby/vendor_ruby/
/usr/lib/ruby/vendor_ruby/treetop/
/usr/lib/ruby/vendor_ruby/treetop/polyglot.rb
/usr/lib/ruby/vendor_ruby/treetop/bootstrap_gen_1_metagrammar.rb
/usr/lib/ruby/vendor_ruby/treetop/runtime/
/usr/lib/ruby/vendor_ruby/treetop/runtime/interval_skip_list.rb
/usr/lib/ruby/vendor_ruby/treetop/runtime/terminal_parse_failure.rb
/usr/lib/ruby/vendor_ruby/treetop/runtime/compiled_parser.rb
/usr/lib/ruby/vendor_ruby/treetop/runtime/interval_skip_list/
/usr/lib/ruby/vendor_ruby/treetop/runtime/interval_skip_list/interval_skip_list.rb
/usr/lib/ruby/vendor_ruby/treetop/runtime/interval_skip_list/head_node.rb
/usr/lib/ruby/vendor_ruby/treetop/runtime/interval_skip_list/node.rb
/usr/lib/ruby/vendor_ruby/treetop/runtime/terminal_syntax_node.rb
/usr/lib/ruby/vendor_ruby/treetop/runtime/syntax_node.rb
/usr/lib/ruby/vendor_ruby/treetop/runtime.rb
/usr/lib/ruby/vendor_ruby/treetop/ruby_extensions/
/usr/lib/ruby/vendor_ruby/treetop/ruby_extensions/string.rb
/usr/lib/ruby/vendor_ruby/treetop/compiler.rb
/usr/lib/ruby/vendor_ruby/treetop/compiler/
/usr/lib/ruby/vendor_ruby/treetop/compiler/metagrammar.rb
/usr/lib/ruby/vendor_ruby/treetop/compiler/node_classes.rb
/usr/lib/ruby/vendor_ruby/treetop/compiler/metagrammar.treetop
/usr/lib/ruby/vendor_ruby/treetop/compiler/ruby_builder.rb
/usr/lib/ruby/vendor_ruby/treetop/compiler/node_classes/
/usr/lib/ruby/vendor_ruby/treetop/compiler/node_classes/anything_symbol.rb
/usr/lib/ruby/vendor_ruby/treetop/compiler/node_classes/terminal.rb
/usr/lib/ruby/vendor_ruby/treetop/compiler/node_classes/atomic_expression.rb
/usr/lib/ruby/vendor_ruby/treetop/compiler/node_classes/optional.rb
/usr/lib/ruby/vendor_ruby/treetop/compiler/node_classes/parsing_expression.rb
/usr/lib/ruby/vendor_ruby/treetop/compiler/node_classes/choice.rb
/usr/lib/ruby/vendor_ruby/treetop/compiler/node_classes/grammar.rb
/usr/lib/ruby/vendor_ruby/treetop/compiler/node_classes/declaration_sequence.rb
/usr/lib/ruby/vendor_ruby/treetop/compiler/node_classes/predicate_block.rb
/usr/lib/ruby/vendor_ruby/treetop/compiler/node_classes/treetop_file.rb
/usr/lib/ruby/vendor_ruby/treetop/compiler/node_classes/inline_module.rb
/usr/lib/ruby/vendor_ruby/treetop/compiler/node_classes/sequence.rb
/usr/lib/ruby/vendor_ruby/treetop/compiler/node_classes/transient_prefix.rb
/usr/lib/ruby/vendor_ruby/treetop/compiler/node_classes/character_class.rb
/usr/lib/ruby/vendor_ruby/treetop/compiler/node_classes/predicate.rb
/usr/lib/ruby/vendor_ruby/treetop/compiler/node_classes/parenthesized_expression.rb
/usr/lib/ruby/vendor_ruby/treetop/compiler/node_classes/nonterminal.rb
/usr/lib/ruby/vendor_ruby/treetop/compiler/node_classes/parsing_rule.rb
/usr/lib/ruby/vendor_ruby/treetop/compiler/node_classes/repetition.rb
/usr/lib/ruby/vendor_ruby/treetop/compiler/grammar_compiler.rb
/usr/lib/ruby/vendor_ruby/treetop/compiler/lexical_address_space.rb
/usr/lib/ruby/vendor_ruby/treetop/version.rb
/usr/lib/ruby/vendor_ruby/treetop/ruby_extensions.rb
/usr/lib/ruby/vendor_ruby/treetop.rb