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  [03:39:49.247] Benchmark with 60 resampling iterations 
INFO  [03:39:49.465] Applying learner 'classif.featureless' on task 'spam' (iter 1/10) 
INFO  [03:39:49.527] Applying learner 'classif.featureless' on task 'spam' (iter 2/10) 
INFO  [03:39:49.543] Applying learner 'classif.featureless' on task 'spam' (iter 3/10) 
INFO  [03:39:49.574] Applying learner 'classif.featureless' on task 'spam' (iter 4/10) 
INFO  [03:39:49.590] Applying learner 'classif.featureless' on task 'spam' (iter 5/10) 
INFO  [03:39:49.621] Applying learner 'classif.featureless' on task 'spam' (iter 6/10) 
INFO  [03:39:49.637] Applying learner 'classif.featureless' on task 'spam' (iter 7/10) 
INFO  [03:39:49.668] Applying learner 'classif.featureless' on task 'spam' (iter 8/10) 
INFO  [03:39:49.683] Applying learner 'classif.featureless' on task 'spam' (iter 9/10) 
INFO  [03:39:49.699] Applying learner 'classif.featureless' on task 'spam' (iter 10/10) 
INFO  [03:39:49.730] Applying learner 'classif.rpart' on task 'spam' (iter 1/10) 
INFO  [03:39:49.886] Applying learner 'classif.rpart' on task 'spam' (iter 2/10) 
INFO  [03:39:50.042] Applying learner 'classif.rpart' on task 'spam' (iter 3/10) 
INFO  [03:39:50.198] Applying learner 'classif.rpart' on task 'spam' (iter 4/10) 
INFO  [03:39:50.370] Applying learner 'classif.rpart' on task 'spam' (iter 5/10) 
INFO  [03:39:50.526] Applying learner 'classif.rpart' on task 'spam' (iter 6/10) 
INFO  [03:39:50.697] Applying learner 'classif.rpart' on task 'spam' (iter 7/10) 
INFO  [03:39:50.853] Applying learner 'classif.rpart' on task 'spam' (iter 8/10) 
INFO  [03:39:50.994] Applying learner 'classif.rpart' on task 'spam' (iter 9/10) 
INFO  [03:39:51.165] Applying learner 'classif.rpart' on task 'spam' (iter 10/10) 
INFO  [03:39:51.321] Applying learner 'classif.featureless' on task 'pima' (iter 1/10) 
INFO  [03:39:51.353] Applying learner 'classif.featureless' on task 'pima' (iter 2/10) 
INFO  [03:39:51.368] Applying learner 'classif.featureless' on task 'pima' (iter 3/10) 
INFO  [03:39:51.384] Applying learner 'classif.featureless' on task 'pima' (iter 4/10) 
INFO  [03:39:51.415] Applying learner 'classif.featureless' on task 'pima' (iter 5/10) 
INFO  [03:39:51.446] Applying learner 'classif.featureless' on task 'pima' (iter 6/10) 
INFO  [03:39:51.462] Applying learner 'classif.featureless' on task 'pima' (iter 7/10) 
INFO  [03:39:51.477] Applying learner 'classif.featureless' on task 'pima' (iter 8/10) 
INFO  [03:39:51.509] Applying learner 'classif.featureless' on task 'pima' (iter 9/10) 
INFO  [03:39:51.524] Applying learner 'classif.featureless' on task 'pima' (iter 10/10) 
INFO  [03:39:51.555] Applying learner 'classif.rpart' on task 'pima' (iter 1/10) 
INFO  [03:39:51.602] Applying learner 'classif.rpart' on task 'pima' (iter 2/10) 
INFO  [03:39:51.633] Applying learner 'classif.rpart' on task 'pima' (iter 3/10) 
INFO  [03:39:51.680] Applying learner 'classif.rpart' on task 'pima' (iter 4/10) 
INFO  [03:39:51.727] Applying learner 'classif.rpart' on task 'pima' (iter 5/10) 
INFO  [03:39:51.805] Applying learner 'classif.rpart' on task 'pima' (iter 6/10) 
INFO  [03:39:51.852] Applying learner 'classif.rpart' on task 'pima' (iter 7/10) 
INFO  [03:39:51.883] Applying learner 'classif.rpart' on task 'pima' (iter 8/10) 
INFO  [03:39:51.914] Applying learner 'classif.rpart' on task 'pima' (iter 9/10) 
INFO  [03:39:51.961] Applying learner 'classif.rpart' on task 'pima' (iter 10/10) 
INFO  [03:39:51.992] Applying learner 'classif.featureless' on task 'sonar' (iter 1/10) 
INFO  [03:39:52.023] Applying learner 'classif.featureless' on task 'sonar' (iter 2/10) 
INFO  [03:39:52.039] Applying learner 'classif.featureless' on task 'sonar' (iter 3/10) 
INFO  [03:39:52.070] Applying learner 'classif.featureless' on task 'sonar' (iter 4/10) 
INFO  [03:39:52.086] Applying learner 'classif.featureless' on task 'sonar' (iter 5/10) 
INFO  [03:39:52.117] Applying learner 'classif.featureless' on task 'sonar' (iter 6/10) 
INFO  [03:39:52.148] Applying learner 'classif.featureless' on task 'sonar' (iter 7/10) 
INFO  [03:39:52.179] Applying learner 'classif.featureless' on task 'sonar' (iter 8/10) 
INFO  [03:39:52.195] Applying learner 'classif.featureless' on task 'sonar' (iter 9/10) 
INFO  [03:39:52.226] Applying learner 'classif.featureless' on task 'sonar' (iter 10/10) 
INFO  [03:39:52.257] Applying learner 'classif.rpart' on task 'sonar' (iter 1/10) 
INFO  [03:39:52.320] Applying learner 'classif.rpart' on task 'sonar' (iter 2/10) 
INFO  [03:39:52.398] Applying learner 'classif.rpart' on task 'sonar' (iter 3/10) 
INFO  [03:39:52.460] Applying learner 'classif.rpart' on task 'sonar' (iter 4/10) 
INFO  [03:39:52.538] Applying learner 'classif.rpart' on task 'sonar' (iter 5/10) 
INFO  [03:39:52.601] Applying learner 'classif.rpart' on task 'sonar' (iter 6/10) 
INFO  [03:39:52.647] Applying learner 'classif.rpart' on task 'sonar' (iter 7/10) 
INFO  [03:39:52.710] Applying learner 'classif.rpart' on task 'sonar' (iter 8/10) 
INFO  [03:39:52.772] Applying learner 'classif.rpart' on task 'sonar' (iter 9/10) 
INFO  [03:39:52.835] Applying learner 'classif.rpart' on task 'sonar' (iter 10/10) 
INFO  [03:39:52.897] Finished benchmark 
> 
> head(fortify(object))
Error: $ operator is invalid for atomic vectors
Execution halted