/usr/ is in ruby-solve 3.0.1-1.
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/solve/
/usr/lib/ruby/vendor_ruby/solve/artifact.rb
/usr/lib/ruby/vendor_ruby/solve/constraint.rb
/usr/lib/ruby/vendor_ruby/solve/demand.rb
/usr/lib/ruby/vendor_ruby/solve/dependency.rb
/usr/lib/ruby/vendor_ruby/solve/errors.rb
/usr/lib/ruby/vendor_ruby/solve/gecode_solver.rb
/usr/lib/ruby/vendor_ruby/solve/graph.rb
/usr/lib/ruby/vendor_ruby/solve/ruby_solver.rb
/usr/lib/ruby/vendor_ruby/solve/solver/
/usr/lib/ruby/vendor_ruby/solve/solver/serializer.rb
/usr/lib/ruby/vendor_ruby/solve/version.rb
/usr/lib/ruby/vendor_ruby/solve.rb
/usr/share/
/usr/share/doc/
/usr/share/doc/ruby-solve/
/usr/share/doc/ruby-solve/README.md
/usr/share/doc/ruby-solve/changelog.Debian.gz
/usr/share/doc/ruby-solve/copyright
/usr/share/rubygems-integration/
/usr/share/rubygems-integration/all/
/usr/share/rubygems-integration/all/specifications/
/usr/share/rubygems-integration/all/specifications/solve-3.0.1.gemspec