R tidyverse - parameter data_grid.model

Question

after updating my R environment, I keep getting this error:

Error in overscope_eval_next (overscope, expr): object 'G' not found

The documentation reads: "Model. If supplied, any predictors needed for a model not present in ... will be populated with" typical "values."

This is similar to this example in the documentation. However, there seems to be a problem with this example below. There were no problems with previous versions.

library(tidyverse)
library(hexbin)
library(modelr)
smaller <- diamonds %>% filter(carat < 3)
mod_diamond2 <- lm(price ~ carat + color + cut + clarity, data = smaller)
grid <- smaller %>%  data_grid(cut, .model = mod_diamond2) %>% 
add_predictions(mod_diamond2)

Any ideas? thanks in advance