Running examples in ‘recipes-Ex.R’ failed
The error most likely occurred in:

> base::assign(".ptime", proc.time(), pos = "CheckExEnv")
> ### Name: step_impute_knn
> ### Title: Impute via k-nearest neighbors
> ### Aliases: step_impute_knn step_knnimpute
> 
> ### ** Examples
> 
> ## Don't show: 
> if (rlang::is_installed("modeldata")) (if (getRversion() >= "3.4") withAutoprint else force)({ # examplesIf
+ ## End(Don't show)
+ library(recipes)
+ data(biomass, package = "modeldata")
+ 
+ biomass_tr <- biomass[biomass$dataset == "Training", ]
+ biomass_te <- biomass[biomass$dataset == "Testing", ]
+ biomass_te_whole <- biomass_te
+ 
+ # induce some missing data at random
+ set.seed(9039)
+ carb_missing <- sample(1:nrow(biomass_te), 3)
+ nitro_missing <- sample(1:nrow(biomass_te), 3)
+ 
+ biomass_te$carbon[carb_missing] <- NA
+ biomass_te$nitrogen[nitro_missing] <- NA
+ 
+ rec <- recipe(
+   HHV ~ carbon + hydrogen + oxygen + nitrogen + sulfur,
+   data = biomass_tr
+ )
+ 
+ ratio_recipe <- rec %>%
+   step_impute_knn(all_predictors(), neighbors = 3)
+ ratio_recipe2 <- prep(ratio_recipe, training = biomass_tr)
+ imputed <- bake(ratio_recipe2, biomass_te)
+ 
+ # how well did it work?
+ summary(biomass_te_whole$carbon)
+ cbind(
+   before = biomass_te_whole$carbon[carb_missing],
+   after = imputed$carbon[carb_missing]
+ )
+ 
+ summary(biomass_te_whole$nitrogen)
+ cbind(
+   before = biomass_te_whole$nitrogen[nitro_missing],
+   after = imputed$nitrogen[nitro_missing]
+ )
+ 
+ tidy(ratio_recipe, number = 1)
+ tidy(ratio_recipe2, number = 1)
+ ## Don't show: 
+ }) # examplesIf
> library(recipes)
> data(biomass, package = "modeldata")
> biomass_tr <- biomass[biomass$dataset == "Training", ]
> biomass_te <- biomass[biomass$dataset == "Testing", ]
> biomass_te_whole <- biomass_te
> set.seed(9039)
> carb_missing <- sample(1:nrow(biomass_te), 3)
> nitro_missing <- sample(1:nrow(biomass_te), 3)
> biomass_te$carbon[carb_missing] <- NA
> biomass_te$nitrogen[nitro_missing] <- NA
> rec <- recipe(HHV ~ carbon + hydrogen + oxygen + nitrogen + sulfur, data = biomass_tr)
> ratio_recipe <- rec %>% step_impute_knn(all_predictors(), neighbors = 3)
> ratio_recipe2 <- prep(ratio_recipe, training = biomass_tr)
> imputed <- bake(ratio_recipe2, biomass_te)
Error in vectbl_assign(x[[j]], i, recycled_value[[j]]) : 
  DLL requires the use of native symbols
Calls: <Anonymous> ... tbl_subassign_row -> withCallingHandlers -> vectbl_assign
Execution halted