# File lib/multiruby.rb, line 173
  def self.fetch_tar v
    in_versions_dir do
      warn "  Determining latest version for #{v}"
      ver = v[/\d+\.\d+/]
      base = matching_versions("#{RUBY_URL}/#{ver}/", v).last
      abort "Could not determine release for #{v}" unless base
      url = File.join RUBY_URL, ver, base
      unless File.file? base then
        warn "    Fetching #{base} via HTTP... this might take a while."
        open(url) do |f|
          File.open base, 'w' do |out|
            out.write f.read
          end
        end
      end
    end
  end