/usr/ is in ruby-gollum-lib 4.2.1+debian-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/gollum-lib/
/usr/lib/ruby/vendor_ruby/gollum-lib/blob_entry.rb
/usr/lib/ruby/vendor_ruby/gollum-lib/committer.rb
/usr/lib/ruby/vendor_ruby/gollum-lib/file.rb
/usr/lib/ruby/vendor_ruby/gollum-lib/file_view.rb
/usr/lib/ruby/vendor_ruby/gollum-lib/filter/
/usr/lib/ruby/vendor_ruby/gollum-lib/filter/code.rb
/usr/lib/ruby/vendor_ruby/gollum-lib/filter/macro.rb
/usr/lib/ruby/vendor_ruby/gollum-lib/filter/metadata.rb
/usr/lib/ruby/vendor_ruby/gollum-lib/filter/plain_text.rb
/usr/lib/ruby/vendor_ruby/gollum-lib/filter/plantuml.rb
/usr/lib/ruby/vendor_ruby/gollum-lib/filter/remote_code.rb
/usr/lib/ruby/vendor_ruby/gollum-lib/filter/render.rb
/usr/lib/ruby/vendor_ruby/gollum-lib/filter/sanitize.rb
/usr/lib/ruby/vendor_ruby/gollum-lib/filter/tags.rb
/usr/lib/ruby/vendor_ruby/gollum-lib/filter/toc.rb
/usr/lib/ruby/vendor_ruby/gollum-lib/filter/wsd.rb
/usr/lib/ruby/vendor_ruby/gollum-lib/filter.rb
/usr/lib/ruby/vendor_ruby/gollum-lib/git_access.rb
/usr/lib/ruby/vendor_ruby/gollum-lib/gitcode.rb
/usr/lib/ruby/vendor_ruby/gollum-lib/helpers.rb
/usr/lib/ruby/vendor_ruby/gollum-lib/hook.rb
/usr/lib/ruby/vendor_ruby/gollum-lib/macro/
/usr/share/doc/ruby-gollum-lib/changelog.gz
/usr/lib/ruby/vendor_ruby/gollum-lib/macro/all_pages.rb
/usr/lib/ruby/vendor_ruby/gollum-lib/macro/global_toc.rb
/usr/lib/ruby/vendor_ruby/gollum-lib/macro/navigation.rb
/usr/lib/ruby/vendor_ruby/gollum-lib/macro/series.rb
/usr/lib/ruby/vendor_ruby/gollum-lib/macro.rb
/usr/lib/ruby/vendor_ruby/gollum-lib/markup.rb
/usr/lib/ruby/vendor_ruby/gollum-lib/markups.rb
/usr/lib/ruby/vendor_ruby/gollum-lib/page.rb
/usr/lib/ruby/vendor_ruby/gollum-lib/pagination.rb
/usr/lib/ruby/vendor_ruby/gollum-lib/sanitization.rb
/usr/lib/ruby/vendor_ruby/gollum-lib/version.rb
/usr/lib/ruby/vendor_ruby/gollum-lib/wiki.rb
/usr/lib/ruby/vendor_ruby/gollum-lib.rb
/usr/share/
/usr/share/doc/
/usr/share/doc/ruby-gollum-lib/
/usr/share/doc/ruby-gollum-lib/README.md.gz
/usr/share/doc/ruby-gollum-lib/changelog.Debian.gz
/usr/share/doc/ruby-gollum-lib/copyright
/usr/share/rubygems-integration/
/usr/share/rubygems-integration/all/
/usr/share/rubygems-integration/all/specifications/
/usr/share/rubygems-integration/all/specifications/gollum-lib-4.2.1.gemspec