/usr/lib/ruby/vendor_ruby/1.8/atk.rb is in ruby-atk 1.0.3-1build1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/ruby/vendor_ruby/1.8/../atk.rb
/usr/lib/ruby/vendor_ruby/1.8/../atk.rb