some uses of str.format remain, but converting them would be more trouble than it's worth (cherry picked from commit f17cffa3ec5329988a58c76f8fa4f3fe4846a6fc)
some uses of str.format remain, but converting them would be more trouble than it's worth (cherry picked from commit f17cffa3ec5329988a58c76f8fa4f3fe4846a6fc)