/usr/ is in ruby-markerb 1.1.0-2.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/
/usr/lib/ruby/
/usr/lib/ruby/vendor_ruby/
/usr/lib/ruby/vendor_ruby/generators/
/usr/lib/ruby/vendor_ruby/generators/markerb/
/usr/lib/ruby/vendor_ruby/generators/markerb/mailer/
/usr/lib/ruby/vendor_ruby/generators/markerb/mailer/templates/
/usr/lib/ruby/vendor_ruby/generators/markerb/mailer/templates/layout.markerb
/usr/lib/ruby/vendor_ruby/generators/markerb/mailer/templates/view.markerb
/usr/lib/ruby/vendor_ruby/generators/markerb/mailer/mailer_generator.rb
/usr/lib/ruby/vendor_ruby/markerb/
/usr/lib/ruby/vendor_ruby/markerb/markdown.rb
/usr/lib/ruby/vendor_ruby/markerb/railtie.rb
/usr/lib/ruby/vendor_ruby/markerb/version.rb
/usr/lib/ruby/vendor_ruby/markerb.rb
/usr/share/
/usr/share/rubygems-integration/
/usr/share/rubygems-integration/all/
/usr/share/rubygems-integration/all/specifications/
/usr/share/rubygems-integration/all/specifications/markerb-1.1.0.gemspec
/usr/share/doc/
/usr/share/doc/ruby-markerb/
/usr/share/doc/ruby-markerb/copyright
/usr/share/doc/ruby-markerb/changelog.Debian.gz
/usr/share/doc/ruby-markerb/README.md