FYI The example from #1153 now produces the error below and does not create a plot ```r ggplot(data.frame(a = letters[1:3], y = rnorm(3))) + geom_point(aes(y, y)) + facet_grid(a~a) > Error in scale_apply(layer_data, x_vars, "train", SCALE_X, x_scales) : ```
