Running examples in 'mlr3viz-Ex.R' failed
The error most likely occurred in:

> ### Name: autoplot.BenchmarkResult
> ### Title: Plot for BenchmarkResult
> ### Aliases: autoplot.BenchmarkResult
> 
> ### ** Examples
> 
> library(mlr3)
> library(mlr3viz)
> 
> tasks = tsks(c("spam", "pima", "sonar"))
> learner = lrns(c("classif.featureless", "classif.rpart"),
+   predict_type = "prob")
> resampling = rsmps("cv")
> object = benchmark(benchmark_grid(tasks, learner, resampling))
INFO  [19:03:47.384] Benchmark with 60 resampling iterations 
INFO  [19:03:47.680] Applying learner 'classif.featureless' on task 'spam' (iter 1/10) 
INFO  [19:03:47.743] Applying learner 'classif.featureless' on task 'spam' (iter 2/10) 
INFO  [19:03:47.774] Applying learner 'classif.featureless' on task 'spam' (iter 3/10) 
INFO  [19:03:47.789] Applying learner 'classif.featureless' on task 'spam' (iter 4/10) 
INFO  [19:03:47.821] Applying learner 'classif.featureless' on task 'spam' (iter 5/10) 
INFO  [19:03:47.836] Applying learner 'classif.featureless' on task 'spam' (iter 6/10) 
INFO  [19:03:47.867] Applying learner 'classif.featureless' on task 'spam' (iter 7/10) 
INFO  [19:03:47.899] Applying learner 'classif.featureless' on task 'spam' (iter 8/10) 
INFO  [19:03:47.945] Applying learner 'classif.featureless' on task 'spam' (iter 9/10) 
INFO  [19:03:47.961] Applying learner 'classif.featureless' on task 'spam' (iter 10/10) 
INFO  [19:03:47.992] Applying learner 'classif.rpart' on task 'spam' (iter 1/10) 
INFO  [19:03:48.257] Applying learner 'classif.rpart' on task 'spam' (iter 2/10) 
INFO  [19:03:48.414] Applying learner 'classif.rpart' on task 'spam' (iter 3/10) 
INFO  [19:03:48.570] Applying learner 'classif.rpart' on task 'spam' (iter 4/10) 
INFO  [19:03:48.726] Applying learner 'classif.rpart' on task 'spam' (iter 5/10) 
INFO  [19:03:48.897] Applying learner 'classif.rpart' on task 'spam' (iter 6/10) 
INFO  [19:03:49.053] Applying learner 'classif.rpart' on task 'spam' (iter 7/10) 
INFO  [19:03:49.194] Applying learner 'classif.rpart' on task 'spam' (iter 8/10) 
INFO  [19:03:49.350] Applying learner 'classif.rpart' on task 'spam' (iter 9/10) 
INFO  [19:03:49.506] Applying learner 'classif.rpart' on task 'spam' (iter 10/10) 
INFO  [19:03:49.662] Applying learner 'classif.featureless' on task 'pima' (iter 1/10) 
INFO  [19:03:49.693] Applying learner 'classif.featureless' on task 'pima' (iter 2/10) 
INFO  [19:03:49.708] Applying learner 'classif.featureless' on task 'pima' (iter 3/10) 
INFO  [19:03:49.740] Applying learner 'classif.featureless' on task 'pima' (iter 4/10) 
INFO  [19:03:49.771] Applying learner 'classif.featureless' on task 'pima' (iter 5/10) 
INFO  [19:03:49.802] Applying learner 'classif.featureless' on task 'pima' (iter 6/10) 
INFO  [19:03:49.818] Applying learner 'classif.featureless' on task 'pima' (iter 7/10) 
INFO  [19:03:49.849] Applying learner 'classif.featureless' on task 'pima' (iter 8/10) 
INFO  [19:03:49.864] Applying learner 'classif.featureless' on task 'pima' (iter 9/10) 
INFO  [19:03:49.896] Applying learner 'classif.featureless' on task 'pima' (iter 10/10) 
INFO  [19:03:49.911] Applying learner 'classif.rpart' on task 'pima' (iter 1/10) 
INFO  [19:03:49.958] Applying learner 'classif.rpart' on task 'pima' (iter 2/10) 
INFO  [19:03:50.005] Applying learner 'classif.rpart' on task 'pima' (iter 3/10) 
INFO  [19:03:50.052] Applying learner 'classif.rpart' on task 'pima' (iter 4/10) 
INFO  [19:03:50.083] Applying learner 'classif.rpart' on task 'pima' (iter 5/10) 
INFO  [19:03:50.176] Applying learner 'classif.rpart' on task 'pima' (iter 6/10) 
INFO  [19:03:50.208] Applying learner 'classif.rpart' on task 'pima' (iter 7/10) 
INFO  [19:03:50.254] Applying learner 'classif.rpart' on task 'pima' (iter 8/10) 
INFO  [19:03:50.286] Applying learner 'classif.rpart' on task 'pima' (iter 9/10) 
INFO  [19:03:50.332] Applying learner 'classif.rpart' on task 'pima' (iter 10/10) 
INFO  [19:03:50.379] Applying learner 'classif.featureless' on task 'sonar' (iter 1/10) 
INFO  [19:03:50.395] Applying learner 'classif.featureless' on task 'sonar' (iter 2/10) 
INFO  [19:03:50.426] Applying learner 'classif.featureless' on task 'sonar' (iter 3/10) 
INFO  [19:03:50.442] Applying learner 'classif.featureless' on task 'sonar' (iter 4/10) 
INFO  [19:03:50.457] Applying learner 'classif.featureless' on task 'sonar' (iter 5/10) 
INFO  [19:03:50.473] Applying learner 'classif.featureless' on task 'sonar' (iter 6/10) 
INFO  [19:03:50.535] Applying learner 'classif.featureless' on task 'sonar' (iter 7/10) 
INFO  [19:03:50.566] Applying learner 'classif.featureless' on task 'sonar' (iter 8/10) 
INFO  [19:03:50.582] Applying learner 'classif.featureless' on task 'sonar' (iter 9/10) 
INFO  [19:03:50.598] Applying learner 'classif.featureless' on task 'sonar' (iter 10/10) 
INFO  [19:03:50.629] Applying learner 'classif.rpart' on task 'sonar' (iter 1/10) 
INFO  [19:03:50.676] Applying learner 'classif.rpart' on task 'sonar' (iter 2/10) 
INFO  [19:03:50.754] Applying learner 'classif.rpart' on task 'sonar' (iter 3/10) 
INFO  [19:03:50.800] Applying learner 'classif.rpart' on task 'sonar' (iter 4/10) 
INFO  [19:03:50.863] Applying learner 'classif.rpart' on task 'sonar' (iter 5/10) 
INFO  [19:03:50.925] Applying learner 'classif.rpart' on task 'sonar' (iter 6/10) 
INFO  [19:03:50.988] Applying learner 'classif.rpart' on task 'sonar' (iter 7/10) 
INFO  [19:03:51.050] Applying learner 'classif.rpart' on task 'sonar' (iter 8/10) 
INFO  [19:03:51.097] Applying learner 'classif.rpart' on task 'sonar' (iter 9/10) 
INFO  [19:03:51.175] Applying learner 'classif.rpart' on task 'sonar' (iter 10/10) 
INFO  [19:03:51.237] Finished benchmark 
> 
> head(fortify(object))
Error: $ operator is invalid for atomic vectors
Execution halted