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  [20:34:00.289] Benchmark with 60 resampling iterations 
INFO  [20:34:00.696] Applying learner 'classif.featureless' on task 'spam' (iter 1/10) 
INFO  [20:34:00.808] Applying learner 'classif.featureless' on task 'spam' (iter 2/10) 
INFO  [20:34:00.856] Applying learner 'classif.featureless' on task 'spam' (iter 3/10) 
INFO  [20:34:00.900] Applying learner 'classif.featureless' on task 'spam' (iter 4/10) 
INFO  [20:34:00.965] Applying learner 'classif.featureless' on task 'spam' (iter 5/10) 
INFO  [20:34:01.099] Applying learner 'classif.featureless' on task 'spam' (iter 6/10) 
INFO  [20:34:01.179] Applying learner 'classif.featureless' on task 'spam' (iter 7/10) 
INFO  [20:34:01.250] Applying learner 'classif.featureless' on task 'spam' (iter 8/10) 
INFO  [20:34:01.323] Applying learner 'classif.featureless' on task 'spam' (iter 9/10) 
INFO  [20:34:01.395] Applying learner 'classif.featureless' on task 'spam' (iter 10/10) 
INFO  [20:34:01.468] Applying learner 'classif.rpart' on task 'spam' (iter 1/10) 
INFO  [20:34:01.989] Applying learner 'classif.rpart' on task 'spam' (iter 2/10) 
INFO  [20:34:02.404] Applying learner 'classif.rpart' on task 'spam' (iter 3/10) 
INFO  [20:34:02.840] Applying learner 'classif.rpart' on task 'spam' (iter 4/10) 
INFO  [20:34:03.240] Applying learner 'classif.rpart' on task 'spam' (iter 5/10) 
INFO  [20:34:03.595] Applying learner 'classif.rpart' on task 'spam' (iter 6/10) 
INFO  [20:34:03.923] Applying learner 'classif.rpart' on task 'spam' (iter 7/10) 
INFO  [20:34:04.442] Applying learner 'classif.rpart' on task 'spam' (iter 8/10) 
INFO  [20:34:04.818] Applying learner 'classif.rpart' on task 'spam' (iter 9/10) 
INFO  [20:34:05.195] Applying learner 'classif.rpart' on task 'spam' (iter 10/10) 
INFO  [20:34:05.529] Applying learner 'classif.featureless' on task 'pima' (iter 1/10) 
INFO  [20:34:05.566] Applying learner 'classif.featureless' on task 'pima' (iter 2/10) 
INFO  [20:34:05.608] Applying learner 'classif.featureless' on task 'pima' (iter 3/10) 
INFO  [20:34:05.654] Applying learner 'classif.featureless' on task 'pima' (iter 4/10) 
INFO  [20:34:05.721] Applying learner 'classif.featureless' on task 'pima' (iter 5/10) 
INFO  [20:34:05.781] Applying learner 'classif.featureless' on task 'pima' (iter 6/10) 
INFO  [20:34:05.839] Applying learner 'classif.featureless' on task 'pima' (iter 7/10) 
INFO  [20:34:05.903] Applying learner 'classif.featureless' on task 'pima' (iter 8/10) 
INFO  [20:34:05.960] Applying learner 'classif.featureless' on task 'pima' (iter 9/10) 
INFO  [20:34:06.024] Applying learner 'classif.featureless' on task 'pima' (iter 10/10) 
INFO  [20:34:06.073] Applying learner 'classif.rpart' on task 'pima' (iter 1/10) 
INFO  [20:34:06.161] Applying learner 'classif.rpart' on task 'pima' (iter 2/10) 
INFO  [20:34:06.264] Applying learner 'classif.rpart' on task 'pima' (iter 3/10) 
INFO  [20:34:06.367] Applying learner 'classif.rpart' on task 'pima' (iter 4/10) 
INFO  [20:34:06.452] Applying learner 'classif.rpart' on task 'pima' (iter 5/10) 
INFO  [20:34:06.524] Applying learner 'classif.rpart' on task 'pima' (iter 6/10) 
INFO  [20:34:06.714] Applying learner 'classif.rpart' on task 'pima' (iter 7/10) 
INFO  [20:34:06.815] Applying learner 'classif.rpart' on task 'pima' (iter 8/10) 
INFO  [20:34:06.899] Applying learner 'classif.rpart' on task 'pima' (iter 9/10) 
INFO  [20:34:06.983] Applying learner 'classif.rpart' on task 'pima' (iter 10/10) 
INFO  [20:34:07.091] Applying learner 'classif.featureless' on task 'sonar' (iter 1/10) 
INFO  [20:34:07.152] Applying learner 'classif.featureless' on task 'sonar' (iter 2/10) 
INFO  [20:34:07.192] Applying learner 'classif.featureless' on task 'sonar' (iter 3/10) 
INFO  [20:34:07.229] Applying learner 'classif.featureless' on task 'sonar' (iter 4/10) 
INFO  [20:34:07.288] Applying learner 'classif.featureless' on task 'sonar' (iter 5/10) 
INFO  [20:34:07.354] Applying learner 'classif.featureless' on task 'sonar' (iter 6/10) 
INFO  [20:34:07.416] Applying learner 'classif.featureless' on task 'sonar' (iter 7/10) 
INFO  [20:34:07.466] Applying learner 'classif.featureless' on task 'sonar' (iter 8/10) 
INFO  [20:34:07.538] Applying learner 'classif.featureless' on task 'sonar' (iter 9/10) 
INFO  [20:34:07.630] Applying learner 'classif.featureless' on task 'sonar' (iter 10/10) 
INFO  [20:34:07.708] Applying learner 'classif.rpart' on task 'sonar' (iter 1/10) 
INFO  [20:34:07.886] Applying learner 'classif.rpart' on task 'sonar' (iter 2/10) 
INFO  [20:34:08.049] Applying learner 'classif.rpart' on task 'sonar' (iter 3/10) 
INFO  [20:34:08.233] Applying learner 'classif.rpart' on task 'sonar' (iter 4/10) 
INFO  [20:34:08.390] Applying learner 'classif.rpart' on task 'sonar' (iter 5/10) 
INFO  [20:34:08.626] Applying learner 'classif.rpart' on task 'sonar' (iter 6/10) 
INFO  [20:34:08.786] Applying learner 'classif.rpart' on task 'sonar' (iter 7/10) 
INFO  [20:34:08.953] Applying learner 'classif.rpart' on task 'sonar' (iter 8/10) 
INFO  [20:34:09.102] Applying learner 'classif.rpart' on task 'sonar' (iter 9/10) 
INFO  [20:34:09.253] Applying learner 'classif.rpart' on task 'sonar' (iter 10/10) 
INFO  [20:34:09.412] Finished benchmark 
> 
> head(fortify(object))
Error: $ operator is invalid for atomic vectors
Execution halted