/usr/lib/ruby/vendor_ruby/ is in ruby-solve 3.0.1-1.
This file is owned by root:root, with mode 0o755.
..
/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