def unpack_tarball(tgz)
      Dir.chdir(config.ruby_toplevel_dir) do
        each_compressed_file(tgz) do |path, entry|
          debug "Unpacking file: #{path}"
          File.open(path, 'wb') do |f|
            f.write(entry.read)
          end
        end
      end
    end
def unpack_tarball(tgz)
      Dir.chdir(config.ruby_toplevel_dir) do
        each_compressed_file(tgz) do |path, entry|
          debug "Unpacking file: #{path}"
          File.open(path, 'wb') do |f|
            f.write(entry.read)
          end
        end
      end
    end
Unpack a gzipped tarball stream (specified by `tgz`) into the current
 working directory.