/usr/ is in ruby-em-mongo 0.5.1-1.
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/em-mongo.rb
/usr/lib/ruby/vendor_ruby/em-mongo/
/usr/lib/ruby/vendor_ruby/em-mongo/support.rb
/usr/lib/ruby/vendor_ruby/em-mongo/server_response.rb
/usr/lib/ruby/vendor_ruby/em-mongo/exceptions.rb
/usr/lib/ruby/vendor_ruby/em-mongo/collection.rb
/usr/lib/ruby/vendor_ruby/em-mongo/conversions.rb
/usr/lib/ruby/vendor_ruby/em-mongo/core_ext.rb
/usr/lib/ruby/vendor_ruby/em-mongo/prev.rb
/usr/lib/ruby/vendor_ruby/em-mongo/database.rb
/usr/lib/ruby/vendor_ruby/em-mongo/VERSION
/usr/lib/ruby/vendor_ruby/em-mongo/request_response.rb
/usr/lib/ruby/vendor_ruby/em-mongo/connection.rb
/usr/lib/ruby/vendor_ruby/em-mongo/cursor.rb
/usr/share/
/usr/share/doc/
/usr/share/doc/ruby-em-mongo/
/usr/share/doc/ruby-em-mongo/copyright
/usr/share/doc/ruby-em-mongo/changelog.gz
/usr/share/doc/ruby-em-mongo/examples/
/usr/share/doc/ruby-em-mongo/examples/legacy.rb
/usr/share/doc/ruby-em-mongo/examples/readme.rb
/usr/share/doc/ruby-em-mongo/changelog.Debian.gz
/usr/share/doc/ruby-em-mongo/README.rdoc.gz
/usr/share/rubygems-integration/
/usr/share/rubygems-integration/all/
/usr/share/rubygems-integration/all/specifications/
/usr/share/rubygems-integration/all/specifications/em-mongo-0.5.1.gemspec