/usr/lib/ruby/vendor_ruby/serverspec/matcher/ is in ruby-serverspec 2.18.0-1.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/ruby/vendor_ruby/serverspec/matcher/be_enabled.rb
/usr/lib/ruby/vendor_ruby/serverspec/matcher/be_executable.rb
/usr/lib/ruby/vendor_ruby/serverspec/matcher/be_installed.rb
/usr/lib/ruby/vendor_ruby/serverspec/matcher/be_listening.rb
/usr/lib/ruby/vendor_ruby/serverspec/matcher/be_mounted.rb
/usr/lib/ruby/vendor_ruby/serverspec/matcher/be_reachable.rb
/usr/lib/ruby/vendor_ruby/serverspec/matcher/be_readable.rb
/usr/lib/ruby/vendor_ruby/serverspec/matcher/be_resolvable.rb
/usr/lib/ruby/vendor_ruby/serverspec/matcher/be_running.rb
/usr/lib/ruby/vendor_ruby/serverspec/matcher/be_writable.rb
/usr/lib/ruby/vendor_ruby/serverspec/matcher/belong_to_group.rb
/usr/lib/ruby/vendor_ruby/serverspec/matcher/belong_to_primary_group.rb
/usr/lib/ruby/vendor_ruby/serverspec/matcher/contain.rb
/usr/lib/ruby/vendor_ruby/serverspec/matcher/have_entry.rb
/usr/lib/ruby/vendor_ruby/serverspec/matcher/have_rule.rb
/usr/lib/ruby/vendor_ruby/serverspec/matcher/have_site_application.rb
/usr/lib/ruby/vendor_ruby/serverspec/matcher/have_site_bindings.rb
/usr/lib/ruby/vendor_ruby/serverspec/matcher/have_virtual_dir.rb