# File setup.rb, line 1338
  def dive_into(rel)
    return unless File.dir?("#{@srcdir}/#{rel}")

    dir = File.basename(rel)
    unless File.dir?(dir)
      Dir.mkdir dir
      File.chmod(0755,dir)
    end
    prevdir = Dir.pwd
    Dir.chdir dir
    $stderr.puts '---> ' + rel if verbose?
    @currdir = rel
    yield
    Dir.chdir prevdir
    $stderr.puts '<--- ' + rel if verbose?
    @currdir = File.dirname(rel)
  end