Gem::Util.traverse_parents

# File tmp/rubies/ruby-4.0.0/lib/rubygems/util.rb, line 60
def self.traverse_parents(directory, &block)
  return enum_for __method__, directory unless block_given?

  here = File.expand_path directory
  loop do
    begin
      Dir.chdir here, &block
    rescue StandardError
      Errno::EACCES
    end

    new_here = File.expand_path("..", here)
    return if new_here == here # toplevel
    here = new_here
  end
end