/usr/lib/ is in librarian-puppet 0.9.10+dfsg-1.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/ruby/
/usr/lib/ruby/vendor_ruby/
/usr/lib/ruby/vendor_ruby/librarian/
/usr/lib/ruby/vendor_ruby/librarian/puppet.rb
/usr/lib/ruby/vendor_ruby/librarian/puppet/
/usr/lib/ruby/vendor_ruby/librarian/puppet/templates/
/usr/lib/ruby/vendor_ruby/librarian/puppet/templates/Puppetfile
/usr/lib/ruby/vendor_ruby/librarian/puppet/source.rb
/usr/lib/ruby/vendor_ruby/librarian/puppet/extension.rb
/usr/lib/ruby/vendor_ruby/librarian/puppet/cli.rb
/usr/lib/ruby/vendor_ruby/librarian/puppet/dsl.rb
/usr/lib/ruby/vendor_ruby/librarian/puppet/requirement.rb
/usr/lib/ruby/vendor_ruby/librarian/puppet/version.rb
/usr/lib/ruby/vendor_ruby/librarian/puppet/lockfile/
/usr/lib/ruby/vendor_ruby/librarian/puppet/lockfile/parser.rb
/usr/lib/ruby/vendor_ruby/librarian/puppet/source/
/usr/lib/ruby/vendor_ruby/librarian/puppet/source/forge.rb
/usr/lib/ruby/vendor_ruby/librarian/puppet/source/git.rb
/usr/lib/ruby/vendor_ruby/librarian/puppet/source/path.rb
/usr/lib/ruby/vendor_ruby/librarian/puppet/source/local.rb
/usr/lib/ruby/vendor_ruby/librarian/puppet/source/githubtarball.rb
/usr/lib/ruby/vendor_ruby/librarian/puppet/environment.rb