# File lib/phusion_passenger/abstract_installer.rb, line 442
        def list_parent_directories(dir)
                dirs = []
                components = File.expand_path(dir).split(File::SEPARATOR)
                components.shift # Remove leading /
                components.size.times do |i|
                        dirs << File::SEPARATOR + components[0 .. i].join(File::SEPARATOR)
                end
                return dirs.reverse
        end