/usr/ is in ruby-mail-gpg 0.3.3-1.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/
/usr/lib/ruby/
/usr/lib/ruby/vendor_ruby/
/usr/lib/ruby/vendor_ruby/hkp.rb
/usr/lib/ruby/vendor_ruby/mail/
/usr/lib/ruby/vendor_ruby/mail/gpg/
/usr/lib/ruby/vendor_ruby/mail/gpg/decrypted_part.rb
/usr/lib/ruby/vendor_ruby/mail/gpg/delivery_handler.rb
/usr/lib/ruby/vendor_ruby/mail/gpg/encrypted_part.rb
/usr/lib/ruby/vendor_ruby/mail/gpg/gpgme_ext.rb
/usr/lib/ruby/vendor_ruby/mail/gpg/gpgme_helper.rb
/usr/lib/ruby/vendor_ruby/mail/gpg/inline_decrypted_message.rb
/usr/lib/ruby/vendor_ruby/mail/gpg/inline_signed_message.rb
/usr/lib/ruby/vendor_ruby/mail/gpg/message_patch.rb
/usr/lib/ruby/vendor_ruby/mail/gpg/mime_signed_message.rb
/usr/lib/ruby/vendor_ruby/mail/gpg/missing_keys_error.rb
/usr/lib/ruby/vendor_ruby/mail/gpg/rails/
/usr/lib/ruby/vendor_ruby/mail/gpg/rails/action_mailer_base_patch.rb
/usr/lib/ruby/vendor_ruby/mail/gpg/rails.rb
/usr/lib/ruby/vendor_ruby/mail/gpg/sign_part.rb
/usr/lib/ruby/vendor_ruby/mail/gpg/signed_part.rb
/usr/lib/ruby/vendor_ruby/mail/gpg/verified_part.rb
/usr/lib/ruby/vendor_ruby/mail/gpg/verify_result_attribute.rb
/usr/lib/ruby/vendor_ruby/mail/gpg/version.rb
/usr/lib/ruby/vendor_ruby/mail/gpg/version_part.rb
/usr/lib/ruby/vendor_ruby/mail/gpg.rb
/usr/lib/ruby/vendor_ruby/mail-gpg.rb
/usr/share/
/usr/share/doc/
/usr/share/doc/ruby-mail-gpg/
/usr/share/doc/ruby-mail-gpg/README.md.gz
/usr/share/doc/ruby-mail-gpg/changelog.Debian.gz
/usr/share/doc/ruby-mail-gpg/copyright
/usr/share/rubygems-integration/
/usr/share/rubygems-integration/all/
/usr/share/rubygems-integration/all/specifications/
/usr/share/rubygems-integration/all/specifications/mail-gpg-0.3.3.gemspec