# File lib/bundler/runtime.rb, line 94
    def prune_cache
      FileUtils.mkdir_p(cache_path)
      Bundler.ui.info "Removing outdated .gem files from vendor/cache"
      Pathname.glob(cache_path.join("*.gem").to_s).each do |gem_path|
        cached_spec = Gem::Format.from_file_by_path(gem_path.to_s).spec
        next unless Gem::Platform.match(cached_spec.platform)
        unless specs.any?{|s| s.full_name == cached_spec.full_name }
          Bundler.ui.info "  * #{File.basename(gem_path.to_s)}"
          gem_path.rmtree
        end
      end
    end