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  [18:08:05.393] Benchmark with 60 resampling iterations 
INFO  [18:08:05.627] Applying learner 'classif.featureless' on task 'spam' (iter 1/10) 
INFO  [18:08:05.705] Applying learner 'classif.featureless' on task 'spam' (iter 2/10) 
INFO  [18:08:05.752] Applying learner 'classif.featureless' on task 'spam' (iter 3/10) 
INFO  [18:08:05.783] Applying learner 'classif.featureless' on task 'spam' (iter 4/10) 
INFO  [18:08:05.815] Applying learner 'classif.featureless' on task 'spam' (iter 5/10) 
INFO  [18:08:05.846] Applying learner 'classif.featureless' on task 'spam' (iter 6/10) 
INFO  [18:08:05.861] Applying learner 'classif.featureless' on task 'spam' (iter 7/10) 
INFO  [18:08:05.893] Applying learner 'classif.featureless' on task 'spam' (iter 8/10) 
INFO  [18:08:05.908] Applying learner 'classif.featureless' on task 'spam' (iter 9/10) 
INFO  [18:08:05.939] Applying learner 'classif.featureless' on task 'spam' (iter 10/10) 
INFO  [18:08:05.971] Applying learner 'classif.rpart' on task 'spam' (iter 1/10) 
INFO  [18:08:06.189] Applying learner 'classif.rpart' on task 'spam' (iter 2/10) 
INFO  [18:08:06.376] Applying learner 'classif.rpart' on task 'spam' (iter 3/10) 
INFO  [18:08:06.532] Applying learner 'classif.rpart' on task 'spam' (iter 4/10) 
INFO  [18:08:06.735] Applying learner 'classif.rpart' on task 'spam' (iter 5/10) 
INFO  [18:08:06.891] Applying learner 'classif.rpart' on task 'spam' (iter 6/10) 
INFO  [18:08:07.047] Applying learner 'classif.rpart' on task 'spam' (iter 7/10) 
INFO  [18:08:07.265] Applying learner 'classif.rpart' on task 'spam' (iter 8/10) 
INFO  [18:08:07.437] Applying learner 'classif.rpart' on task 'spam' (iter 9/10) 
INFO  [18:08:07.624] Applying learner 'classif.rpart' on task 'spam' (iter 10/10) 
INFO  [18:08:07.780] Applying learner 'classif.featureless' on task 'pima' (iter 1/10) 
INFO  [18:08:07.796] Applying learner 'classif.featureless' on task 'pima' (iter 2/10) 
INFO  [18:08:07.811] Applying learner 'classif.featureless' on task 'pima' (iter 3/10) 
INFO  [18:08:07.827] Applying learner 'classif.featureless' on task 'pima' (iter 4/10) 
INFO  [18:08:07.858] Applying learner 'classif.featureless' on task 'pima' (iter 5/10) 
INFO  [18:08:07.889] Applying learner 'classif.featureless' on task 'pima' (iter 6/10) 
INFO  [18:08:07.905] Applying learner 'classif.featureless' on task 'pima' (iter 7/10) 
INFO  [18:08:07.921] Applying learner 'classif.featureless' on task 'pima' (iter 8/10) 
INFO  [18:08:07.952] Applying learner 'classif.featureless' on task 'pima' (iter 9/10) 
INFO  [18:08:07.967] Applying learner 'classif.featureless' on task 'pima' (iter 10/10) 
INFO  [18:08:07.983] Applying learner 'classif.rpart' on task 'pima' (iter 1/10) 
INFO  [18:08:08.061] Applying learner 'classif.rpart' on task 'pima' (iter 2/10) 
INFO  [18:08:08.108] Applying learner 'classif.rpart' on task 'pima' (iter 3/10) 
INFO  [18:08:08.139] Applying learner 'classif.rpart' on task 'pima' (iter 4/10) 
INFO  [18:08:08.170] Applying learner 'classif.rpart' on task 'pima' (iter 5/10) 
INFO  [18:08:08.217] Applying learner 'classif.rpart' on task 'pima' (iter 6/10) 
INFO  [18:08:08.248] Applying learner 'classif.rpart' on task 'pima' (iter 7/10) 
INFO  [18:08:08.279] Applying learner 'classif.rpart' on task 'pima' (iter 8/10) 
INFO  [18:08:08.326] Applying learner 'classif.rpart' on task 'pima' (iter 9/10) 
INFO  [18:08:08.373] Applying learner 'classif.rpart' on task 'pima' (iter 10/10) 
INFO  [18:08:08.404] Applying learner 'classif.featureless' on task 'sonar' (iter 1/10) 
INFO  [18:08:08.420] Applying learner 'classif.featureless' on task 'sonar' (iter 2/10) 
INFO  [18:08:08.451] Applying learner 'classif.featureless' on task 'sonar' (iter 3/10) 
INFO  [18:08:08.467] Applying learner 'classif.featureless' on task 'sonar' (iter 4/10) 
INFO  [18:08:08.498] Applying learner 'classif.featureless' on task 'sonar' (iter 5/10) 
INFO  [18:08:08.513] Applying learner 'classif.featureless' on task 'sonar' (iter 6/10) 
INFO  [18:08:08.529] Applying learner 'classif.featureless' on task 'sonar' (iter 7/10) 
INFO  [18:08:08.560] Applying learner 'classif.featureless' on task 'sonar' (iter 8/10) 
INFO  [18:08:08.576] Applying learner 'classif.featureless' on task 'sonar' (iter 9/10) 
INFO  [18:08:08.591] Applying learner 'classif.featureless' on task 'sonar' (iter 10/10) 
INFO  [18:08:08.623] Applying learner 'classif.rpart' on task 'sonar' (iter 1/10) 
INFO  [18:08:08.685] Applying learner 'classif.rpart' on task 'sonar' (iter 2/10) 
INFO  [18:08:08.732] Applying learner 'classif.rpart' on task 'sonar' (iter 3/10) 
INFO  [18:08:08.794] Applying learner 'classif.rpart' on task 'sonar' (iter 4/10) 
INFO  [18:08:08.857] Applying learner 'classif.rpart' on task 'sonar' (iter 5/10) 
INFO  [18:08:08.903] Applying learner 'classif.rpart' on task 'sonar' (iter 6/10) 
INFO  [18:08:08.966] Applying learner 'classif.rpart' on task 'sonar' (iter 7/10) 
INFO  [18:08:09.028] Applying learner 'classif.rpart' on task 'sonar' (iter 8/10) 
INFO  [18:08:09.106] Applying learner 'classif.rpart' on task 'sonar' (iter 9/10) 
INFO  [18:08:09.153] Applying learner 'classif.rpart' on task 'sonar' (iter 10/10) 
INFO  [18:08:09.215] Finished benchmark 
> 
> head(fortify(object))
Error: $ operator is invalid for atomic vectors
Execution halted