/usr/ is in ruby-slack-notifier 1.5.1-1.
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/slack-notifier/
/usr/lib/ruby/vendor_ruby/slack-notifier/default_http_client.rb
/usr/lib/ruby/vendor_ruby/slack-notifier/link_formatter.rb
/usr/lib/ruby/vendor_ruby/slack-notifier/version.rb
/usr/lib/ruby/vendor_ruby/slack-notifier.rb
/usr/share/
/usr/share/doc/
/usr/share/doc/ruby-slack-notifier/
/usr/share/doc/ruby-slack-notifier/changelog.Debian.gz
/usr/share/doc/ruby-slack-notifier/copyright
/usr/share/rubygems-integration/
/usr/share/rubygems-integration/all/
/usr/share/rubygems-integration/all/specifications/
/usr/share/rubygems-integration/all/specifications/slack-notifier-1.5.1.gemspec