/usr/ is in ruby-cal-heatmap-rails 3.6.0+dfsg-1.
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/cal/
/usr/lib/ruby/vendor_ruby/cal/heatmap/
/usr/lib/ruby/vendor_ruby/cal/heatmap/rails/
/usr/lib/ruby/vendor_ruby/cal/heatmap/rails/version.rb
/usr/lib/ruby/vendor_ruby/cal/heatmap/rails.rb
/usr/share/
/usr/share/doc/
/usr/share/doc/ruby-cal-heatmap-rails/
/usr/share/doc/ruby-cal-heatmap-rails/changelog.Debian.gz
/usr/share/doc/ruby-cal-heatmap-rails/copyright
/usr/share/ruby-cal-heatmap-rails/
/usr/share/ruby-cal-heatmap-rails/vendor/
/usr/share/ruby-cal-heatmap-rails/vendor/assets/
/usr/share/ruby-cal-heatmap-rails/vendor/assets/javascripts/
/usr/share/ruby-cal-heatmap-rails/vendor/assets/javascripts/cal-heatmap.js
/usr/share/ruby-cal-heatmap-rails/vendor/assets/javascripts/cal-heatmap.min.js
/usr/share/ruby-cal-heatmap-rails/vendor/assets/stylesheets/
/usr/share/ruby-cal-heatmap-rails/vendor/assets/stylesheets/cal-heatmap.css
/usr/share/rubygems-integration/
/usr/share/rubygems-integration/all/
/usr/share/rubygems-integration/all/specifications/
/usr/share/rubygems-integration/all/specifications/cal-heatmap-rails-3.6.0.gemspec