/usr/ is in ruby-ref 2.0.0-1.
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/usr/share/rubygems-integration/all/
/usr/share/rubygems-integration/all/specifications/
/usr/share/
/usr/share/rubygems-integration/
/usr/share/rubygems-integration/all/specifications/ref-2.0.0.gemspec
/usr/share/doc/
/usr/share/doc/ruby-ref/
/usr/share/doc/ruby-ref/copyright
/usr/share/doc/ruby-ref/README.md
/usr/share/doc/ruby-ref/changelog.Debian.gz
/usr/lib/
/usr/lib/ruby/
/usr/lib/ruby/vendor_ruby/
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/usr/lib/ruby/vendor_ruby/ref/
/usr/lib/ruby/vendor_ruby/ref/soft_reference.rb
/usr/lib/ruby/vendor_ruby/ref/strong_reference.rb
/usr/lib/ruby/vendor_ruby/ref/weak_reference/
/usr/lib/ruby/vendor_ruby/ref/weak_reference/pure_ruby.rb
/usr/lib/ruby/vendor_ruby/ref/weak_reference/weak_ref.rb
/usr/lib/ruby/vendor_ruby/ref/reference_queue.rb
/usr/lib/ruby/vendor_ruby/ref/weak_value_map.rb
/usr/lib/ruby/vendor_ruby/ref/soft_value_map.rb
/usr/lib/ruby/vendor_ruby/ref/abstract_reference_value_map.rb
/usr/lib/ruby/vendor_ruby/ref/soft_key_map.rb
/usr/lib/ruby/vendor_ruby/ref/weak_reference.rb
/usr/lib/ruby/vendor_ruby/ref/abstract_reference_key_map.rb
/usr/lib/ruby/vendor_ruby/ref/weak_key_map.rb
/usr/lib/ruby/vendor_ruby/ref/reference.rb
/usr/lib/ruby/vendor_ruby/ref/version.rb