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  [13:54:18.898] Benchmark with 60 resampling iterations 
INFO  [13:54:19.069] Applying learner 'classif.featureless' on task 'spam' (iter 1/10) 
INFO  [13:54:19.101] Applying learner 'classif.featureless' on task 'spam' (iter 2/10) 
INFO  [13:54:19.116] Applying learner 'classif.featureless' on task 'spam' (iter 3/10) 
INFO  [13:54:19.132] Applying learner 'classif.featureless' on task 'spam' (iter 4/10) 
INFO  [13:54:19.147] Applying learner 'classif.featureless' on task 'spam' (iter 5/10) 
INFO  [13:54:19.163] Applying learner 'classif.featureless' on task 'spam' (iter 6/10) 
INFO  [13:54:19.179] Applying learner 'classif.featureless' on task 'spam' (iter 7/10) 
INFO  [13:54:19.194] Applying learner 'classif.featureless' on task 'spam' (iter 8/10) 
INFO  [13:54:19.225] Applying learner 'classif.featureless' on task 'spam' (iter 9/10) 
INFO  [13:54:19.241] Applying learner 'classif.featureless' on task 'spam' (iter 10/10) 
INFO  [13:54:19.256] Applying learner 'classif.rpart' on task 'spam' (iter 1/10) 
INFO  [13:54:19.428] Applying learner 'classif.rpart' on task 'spam' (iter 2/10) 
INFO  [13:54:19.537] Applying learner 'classif.rpart' on task 'spam' (iter 3/10) 
INFO  [13:54:19.662] Applying learner 'classif.rpart' on task 'spam' (iter 4/10) 
INFO  [13:54:19.771] Applying learner 'classif.rpart' on task 'spam' (iter 5/10) 
INFO  [13:54:19.880] Applying learner 'classif.rpart' on task 'spam' (iter 6/10) 
INFO  [13:54:20.021] Applying learner 'classif.rpart' on task 'spam' (iter 7/10) 
INFO  [13:54:20.145] Applying learner 'classif.rpart' on task 'spam' (iter 8/10) 
INFO  [13:54:20.255] Applying learner 'classif.rpart' on task 'spam' (iter 9/10) 
INFO  [13:54:20.379] Applying learner 'classif.rpart' on task 'spam' (iter 10/10) 
INFO  [13:54:20.504] Applying learner 'classif.featureless' on task 'pima' (iter 1/10) 
INFO  [13:54:20.520] Applying learner 'classif.featureless' on task 'pima' (iter 2/10) 
INFO  [13:54:20.551] Applying learner 'classif.featureless' on task 'pima' (iter 3/10) 
INFO  [13:54:20.567] Applying learner 'classif.featureless' on task 'pima' (iter 4/10) 
INFO  [13:54:20.598] Applying learner 'classif.featureless' on task 'pima' (iter 5/10) 
INFO  [13:54:20.613] Applying learner 'classif.featureless' on task 'pima' (iter 6/10) 
INFO  [13:54:20.629] Applying learner 'classif.featureless' on task 'pima' (iter 7/10) 
INFO  [13:54:20.645] Applying learner 'classif.featureless' on task 'pima' (iter 8/10) 
INFO  [13:54:20.660] Applying learner 'classif.featureless' on task 'pima' (iter 9/10) 
INFO  [13:54:20.676] Applying learner 'classif.featureless' on task 'pima' (iter 10/10) 
INFO  [13:54:20.691] Applying learner 'classif.rpart' on task 'pima' (iter 1/10) 
INFO  [13:54:20.722] Applying learner 'classif.rpart' on task 'pima' (iter 2/10) 
INFO  [13:54:20.738] Applying learner 'classif.rpart' on task 'pima' (iter 3/10) 
INFO  [13:54:20.769] Applying learner 'classif.rpart' on task 'pima' (iter 4/10) 
INFO  [13:54:20.785] Applying learner 'classif.rpart' on task 'pima' (iter 5/10) 
INFO  [13:54:20.847] Applying learner 'classif.rpart' on task 'pima' (iter 6/10) 
INFO  [13:54:20.878] Applying learner 'classif.rpart' on task 'pima' (iter 7/10) 
INFO  [13:54:20.894] Applying learner 'classif.rpart' on task 'pima' (iter 8/10) 
INFO  [13:54:20.925] Applying learner 'classif.rpart' on task 'pima' (iter 9/10) 
INFO  [13:54:20.956] Applying learner 'classif.rpart' on task 'pima' (iter 10/10) 
INFO  [13:54:20.988] Applying learner 'classif.featureless' on task 'sonar' (iter 1/10) 
INFO  [13:54:20.988] Applying learner 'classif.featureless' on task 'sonar' (iter 2/10) 
INFO  [13:54:21.019] Applying learner 'classif.featureless' on task 'sonar' (iter 3/10) 
INFO  [13:54:21.034] Applying learner 'classif.featureless' on task 'sonar' (iter 4/10) 
INFO  [13:54:21.034] Applying learner 'classif.featureless' on task 'sonar' (iter 5/10) 
INFO  [13:54:21.050] Applying learner 'classif.featureless' on task 'sonar' (iter 6/10) 
INFO  [13:54:21.066] Applying learner 'classif.featureless' on task 'sonar' (iter 7/10) 
INFO  [13:54:21.097] Applying learner 'classif.featureless' on task 'sonar' (iter 8/10) 
INFO  [13:54:21.112] Applying learner 'classif.featureless' on task 'sonar' (iter 9/10) 
INFO  [13:54:21.128] Applying learner 'classif.featureless' on task 'sonar' (iter 10/10) 
INFO  [13:54:21.159] Applying learner 'classif.rpart' on task 'sonar' (iter 1/10) 
INFO  [13:54:21.206] Applying learner 'classif.rpart' on task 'sonar' (iter 2/10) 
INFO  [13:54:21.253] Applying learner 'classif.rpart' on task 'sonar' (iter 3/10) 
INFO  [13:54:21.284] Applying learner 'classif.rpart' on task 'sonar' (iter 4/10) 
INFO  [13:54:21.362] Applying learner 'classif.rpart' on task 'sonar' (iter 5/10) 
INFO  [13:54:21.393] Applying learner 'classif.rpart' on task 'sonar' (iter 6/10) 
INFO  [13:54:21.440] Applying learner 'classif.rpart' on task 'sonar' (iter 7/10) 
INFO  [13:54:21.487] Applying learner 'classif.rpart' on task 'sonar' (iter 8/10) 
INFO  [13:54:21.533] Applying learner 'classif.rpart' on task 'sonar' (iter 9/10) 
INFO  [13:54:21.596] Applying learner 'classif.rpart' on task 'sonar' (iter 10/10) 
INFO  [13:54:21.674] Finished benchmark 
> 
> head(fortify(object))
Error: $ operator is invalid for atomic vectors
Execution halted