/usr/lib/ruby/ is in libvalidatable-ruby1.9.1 1.6.7-6.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/ruby/1.9.1/
/usr/lib/ruby/1.9.1/macros.rb
/usr/lib/ruby/1.9.1/validatable_class_methods.rb
/usr/lib/ruby/1.9.1/requireable.rb
/usr/lib/ruby/1.9.1/child_validation.rb
/usr/lib/ruby/1.9.1/included_validation.rb
/usr/lib/ruby/1.9.1/validatable.rb
/usr/lib/ruby/1.9.1/errors.rb
/usr/lib/ruby/1.9.1/validatable_instance_methods.rb
/usr/lib/ruby/1.9.1/understandable.rb
/usr/lib/ruby/1.9.1/object_extension.rb
/usr/lib/ruby/1.9.1/validations/
/usr/lib/ruby/1.9.1/validations/validates_numericality_of.rb
/usr/lib/ruby/1.9.1/validations/validation_base.rb
/usr/lib/ruby/1.9.1/validations/validates_acceptance_of.rb
/usr/lib/ruby/1.9.1/validations/validates_presence_of.rb
/usr/lib/ruby/1.9.1/validations/validates_length_of.rb
/usr/lib/ruby/1.9.1/validations/validates_each.rb
/usr/lib/ruby/1.9.1/validations/validates_format_of.rb
/usr/lib/ruby/1.9.1/validations/validates_true_for.rb
/usr/lib/ruby/1.9.1/validations/validates_confirmation_of.rb