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  [01:05:14.052] Benchmark with 60 resampling iterations 
INFO  [01:05:14.176] Applying learner 'classif.featureless' on task 'spam' (iter 1/10) 
INFO  [01:05:14.208] Applying learner 'classif.featureless' on task 'spam' (iter 2/10) 
INFO  [01:05:14.223] Applying learner 'classif.featureless' on task 'spam' (iter 3/10) 
INFO  [01:05:14.239] Applying learner 'classif.featureless' on task 'spam' (iter 4/10) 
INFO  [01:05:14.254] Applying learner 'classif.featureless' on task 'spam' (iter 5/10) 
INFO  [01:05:14.270] Applying learner 'classif.featureless' on task 'spam' (iter 6/10) 
INFO  [01:05:14.270] Applying learner 'classif.featureless' on task 'spam' (iter 7/10) 
INFO  [01:05:14.286] Applying learner 'classif.featureless' on task 'spam' (iter 8/10) 
INFO  [01:05:14.301] Applying learner 'classif.featureless' on task 'spam' (iter 9/10) 
INFO  [01:05:14.317] Applying learner 'classif.featureless' on task 'spam' (iter 10/10) 
INFO  [01:05:14.317] Applying learner 'classif.rpart' on task 'spam' (iter 1/10) 
INFO  [01:05:14.442] Applying learner 'classif.rpart' on task 'spam' (iter 2/10) 
INFO  [01:05:14.535] Applying learner 'classif.rpart' on task 'spam' (iter 3/10) 
INFO  [01:05:14.644] Applying learner 'classif.rpart' on task 'spam' (iter 4/10) 
INFO  [01:05:14.738] Applying learner 'classif.rpart' on task 'spam' (iter 5/10) 
INFO  [01:05:14.832] Applying learner 'classif.rpart' on task 'spam' (iter 6/10) 
INFO  [01:05:14.925] Applying learner 'classif.rpart' on task 'spam' (iter 7/10) 
INFO  [01:05:15.019] Applying learner 'classif.rpart' on task 'spam' (iter 8/10) 
INFO  [01:05:15.128] Applying learner 'classif.rpart' on task 'spam' (iter 9/10) 
INFO  [01:05:15.222] Applying learner 'classif.rpart' on task 'spam' (iter 10/10) 
INFO  [01:05:15.315] Applying learner 'classif.featureless' on task 'pima' (iter 1/10) 
INFO  [01:05:15.331] Applying learner 'classif.featureless' on task 'pima' (iter 2/10) 
INFO  [01:05:15.331] Applying learner 'classif.featureless' on task 'pima' (iter 3/10) 
INFO  [01:05:15.346] Applying learner 'classif.featureless' on task 'pima' (iter 4/10) 
INFO  [01:05:15.362] Applying learner 'classif.featureless' on task 'pima' (iter 5/10) 
INFO  [01:05:15.378] Applying learner 'classif.featureless' on task 'pima' (iter 6/10) 
INFO  [01:05:15.393] Applying learner 'classif.featureless' on task 'pima' (iter 7/10) 
INFO  [01:05:15.393] Applying learner 'classif.featureless' on task 'pima' (iter 8/10) 
INFO  [01:05:15.409] Applying learner 'classif.featureless' on task 'pima' (iter 9/10) 
INFO  [01:05:15.424] Applying learner 'classif.featureless' on task 'pima' (iter 10/10) 
INFO  [01:05:15.440] Applying learner 'classif.rpart' on task 'pima' (iter 1/10) 
INFO  [01:05:15.487] Applying learner 'classif.rpart' on task 'pima' (iter 2/10) 
INFO  [01:05:15.518] Applying learner 'classif.rpart' on task 'pima' (iter 3/10) 
INFO  [01:05:15.549] Applying learner 'classif.rpart' on task 'pima' (iter 4/10) 
INFO  [01:05:15.596] Applying learner 'classif.rpart' on task 'pima' (iter 5/10) 
INFO  [01:05:15.627] Applying learner 'classif.rpart' on task 'pima' (iter 6/10) 
INFO  [01:05:15.674] Applying learner 'classif.rpart' on task 'pima' (iter 7/10) 
INFO  [01:05:15.705] Applying learner 'classif.rpart' on task 'pima' (iter 8/10) 
INFO  [01:05:15.736] Applying learner 'classif.rpart' on task 'pima' (iter 9/10) 
INFO  [01:05:15.768] Applying learner 'classif.rpart' on task 'pima' (iter 10/10) 
INFO  [01:05:15.799] Applying learner 'classif.featureless' on task 'sonar' (iter 1/10) 
INFO  [01:05:15.830] Applying learner 'classif.featureless' on task 'sonar' (iter 2/10) 
INFO  [01:05:15.846] Applying learner 'classif.featureless' on task 'sonar' (iter 3/10) 
INFO  [01:05:15.861] Applying learner 'classif.featureless' on task 'sonar' (iter 4/10) 
INFO  [01:05:15.877] Applying learner 'classif.featureless' on task 'sonar' (iter 5/10) 
INFO  [01:05:15.908] Applying learner 'classif.featureless' on task 'sonar' (iter 6/10) 
INFO  [01:05:15.924] Applying learner 'classif.featureless' on task 'sonar' (iter 7/10) 
INFO  [01:05:15.939] Applying learner 'classif.featureless' on task 'sonar' (iter 8/10) 
INFO  [01:05:15.970] Applying learner 'classif.featureless' on task 'sonar' (iter 9/10) 
INFO  [01:05:15.986] Applying learner 'classif.featureless' on task 'sonar' (iter 10/10) 
INFO  [01:05:16.002] Applying learner 'classif.rpart' on task 'sonar' (iter 1/10) 
INFO  [01:05:16.064] Applying learner 'classif.rpart' on task 'sonar' (iter 2/10) 
INFO  [01:05:16.126] Applying learner 'classif.rpart' on task 'sonar' (iter 3/10) 
INFO  [01:05:16.189] Applying learner 'classif.rpart' on task 'sonar' (iter 4/10) 
INFO  [01:05:16.251] Applying learner 'classif.rpart' on task 'sonar' (iter 5/10) 
INFO  [01:05:16.298] Applying learner 'classif.rpart' on task 'sonar' (iter 6/10) 
INFO  [01:05:16.360] Applying learner 'classif.rpart' on task 'sonar' (iter 7/10) 
INFO  [01:05:16.423] Applying learner 'classif.rpart' on task 'sonar' (iter 8/10) 
INFO  [01:05:16.485] Applying learner 'classif.rpart' on task 'sonar' (iter 9/10) 
INFO  [01:05:16.548] Applying learner 'classif.rpart' on task 'sonar' (iter 10/10) 
INFO  [01:05:16.594] Finished benchmark 
> 
> head(fortify(object))
Error: $ operator is invalid for atomic vectors
Execution halted