/usr/lib/ruby/vendor_ruby/ is in ruby-json-spec 1.1.2-1.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/ruby/vendor_ruby/json_spec/
/usr/lib/ruby/vendor_ruby/json_spec/messages.rb
/usr/lib/ruby/vendor_ruby/json_spec/exclusion.rb
/usr/lib/ruby/vendor_ruby/json_spec/errors.rb
/usr/lib/ruby/vendor_ruby/json_spec/cucumber.rb
/usr/lib/ruby/vendor_ruby/json_spec/helpers.rb
/usr/lib/ruby/vendor_ruby/json_spec/memory.rb
/usr/lib/ruby/vendor_ruby/json_spec/configuration.rb
/usr/lib/ruby/vendor_ruby/json_spec/matchers.rb
/usr/lib/ruby/vendor_ruby/json_spec/matchers/
/usr/lib/ruby/vendor_ruby/json_spec/matchers/have_json_type.rb
/usr/lib/ruby/vendor_ruby/json_spec/matchers/include_json.rb
/usr/lib/ruby/vendor_ruby/json_spec/matchers/have_json_size.rb
/usr/lib/ruby/vendor_ruby/json_spec/matchers/be_json_eql.rb
/usr/lib/ruby/vendor_ruby/json_spec/matchers/have_json_path.rb
/usr/lib/ruby/vendor_ruby/json_spec.rb