/usr/lib/ruby/vendor_ruby/ is in ruby-valid 1.0.0-2.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/ruby/vendor_ruby/validation.rb
/usr/lib/ruby/vendor_ruby/validation/
/usr/lib/ruby/vendor_ruby/validation/version.rb
/usr/lib/ruby/vendor_ruby/validation/rule/
/usr/lib/ruby/vendor_ruby/validation/rule/uri.rb
/usr/lib/ruby/vendor_ruby/validation/rule/matches.rb
/usr/lib/ruby/vendor_ruby/validation/rule/numeric.rb
/usr/lib/ruby/vendor_ruby/validation/rule/uuid.rb
/usr/lib/ruby/vendor_ruby/validation/rule/email.rb
/usr/lib/ruby/vendor_ruby/validation/rule/not_empty.rb
/usr/lib/ruby/vendor_ruby/validation/rule/length.rb
/usr/lib/ruby/vendor_ruby/validation/rule/phone.rb
/usr/lib/ruby/vendor_ruby/validation/rule/regular_expression.rb
/usr/lib/ruby/vendor_ruby/validation/validator.rb