I installed parsnip and tried to fit a very simple random forest model. I ran this code: ``` library(parsnip) library(titanic) rand_forest() %>% set_mode("classification") %>% set_engine("randomForest") %>% set_args(trees = 1000, importance = TRUE) %>% fit(factor(Survived) ~ factor(Sex) + factor(Embarked), data = titanic_train) ``` It returned an error: ``` Error in as.data.frame.default(x) : cannot coerce class ‘c("rand_forest", "model_spec")’ to a data.frame ``` It took me quite some time to figure out the solution was easy: `install.package('randomForest')` It would be nice to get an error message that clearly states the problem: the randomForest package isn't installed.