/usr/ is in ruby-mysql2 0.4.10-0ubuntu5.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/x86_64-linux-gnu/ruby/vendor_ruby/
/usr/lib/
/usr/lib/ruby/
/usr/lib/ruby/vendor_ruby/
/usr/lib/ruby/vendor_ruby/mysql2/
/usr/lib/ruby/vendor_ruby/mysql2/client.rb
/usr/lib/ruby/vendor_ruby/mysql2/console.rb
/usr/lib/ruby/vendor_ruby/mysql2/em.rb
/usr/lib/ruby/vendor_ruby/mysql2/error.rb
/usr/lib/ruby/vendor_ruby/mysql2/field.rb
/usr/lib/ruby/vendor_ruby/mysql2/result.rb
/usr/lib/ruby/vendor_ruby/mysql2/statement.rb
/usr/lib/ruby/vendor_ruby/mysql2/version.rb
/usr/lib/ruby/vendor_ruby/mysql2.rb
/usr/lib/x86_64-linux-gnu/
/usr/lib/x86_64-linux-gnu/ruby/
/usr/lib/x86_64-linux-gnu/ruby/vendor_ruby/2.5.0/
/usr/lib/x86_64-linux-gnu/ruby/vendor_ruby/2.5.0/mysql2/
/usr/lib/x86_64-linux-gnu/ruby/vendor_ruby/2.5.0/mysql2/mysql2.so
/usr/share/
/usr/share/doc/
/usr/share/doc/ruby-mysql2/
/usr/share/doc/ruby-mysql2/README.md.gz
/usr/share/doc/ruby-mysql2/changelog.Debian.gz
/usr/share/doc/ruby-mysql2/copyright
/usr/share/doc/ruby-mysql2/examples/
/usr/share/doc/ruby-mysql2/examples/eventmachine.rb
/usr/share/doc/ruby-mysql2/examples/threaded.rb
/usr/share/rubygems-integration/
/usr/share/rubygems-integration/2.5.0/
/usr/share/rubygems-integration/2.5.0/specifications/
/usr/share/rubygems-integration/2.5.0/specifications/mysql2-0.4.10.gemspec