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  [12:46:34.279] Benchmark with 60 resampling iterations 
INFO  [12:46:34.513] Applying learner 'classif.featureless' on task 'spam' (iter 1/10) 
INFO  [12:46:34.560] Applying learner 'classif.featureless' on task 'spam' (iter 2/10) 
INFO  [12:46:34.591] Applying learner 'classif.featureless' on task 'spam' (iter 3/10) 
INFO  [12:46:34.607] Applying learner 'classif.featureless' on task 'spam' (iter 4/10) 
INFO  [12:46:34.638] Applying learner 'classif.featureless' on task 'spam' (iter 5/10) 
INFO  [12:46:34.654] Applying learner 'classif.featureless' on task 'spam' (iter 6/10) 
INFO  [12:46:34.685] Applying learner 'classif.featureless' on task 'spam' (iter 7/10) 
INFO  [12:46:34.700] Applying learner 'classif.featureless' on task 'spam' (iter 8/10) 
INFO  [12:46:34.732] Applying learner 'classif.featureless' on task 'spam' (iter 9/10) 
INFO  [12:46:34.763] Applying learner 'classif.featureless' on task 'spam' (iter 10/10) 
INFO  [12:46:34.778] Applying learner 'classif.rpart' on task 'spam' (iter 1/10) 
INFO  [12:46:34.950] Applying learner 'classif.rpart' on task 'spam' (iter 2/10) 
INFO  [12:46:35.137] Applying learner 'classif.rpart' on task 'spam' (iter 3/10) 
INFO  [12:46:35.278] Applying learner 'classif.rpart' on task 'spam' (iter 4/10) 
INFO  [12:46:35.434] Applying learner 'classif.rpart' on task 'spam' (iter 5/10) 
INFO  [12:46:35.574] Applying learner 'classif.rpart' on task 'spam' (iter 6/10) 
INFO  [12:46:35.730] Applying learner 'classif.rpart' on task 'spam' (iter 7/10) 
INFO  [12:46:35.902] Applying learner 'classif.rpart' on task 'spam' (iter 8/10) 
INFO  [12:46:36.058] Applying learner 'classif.rpart' on task 'spam' (iter 9/10) 
INFO  [12:46:36.215] Applying learner 'classif.rpart' on task 'spam' (iter 10/10) 
INFO  [12:46:36.355] Applying learner 'classif.featureless' on task 'pima' (iter 1/10) 
INFO  [12:46:36.386] Applying learner 'classif.featureless' on task 'pima' (iter 2/10) 
INFO  [12:46:36.417] Applying learner 'classif.featureless' on task 'pima' (iter 3/10) 
INFO  [12:46:36.449] Applying learner 'classif.featureless' on task 'pima' (iter 4/10) 
INFO  [12:46:36.464] Applying learner 'classif.featureless' on task 'pima' (iter 5/10) 
INFO  [12:46:36.495] Applying learner 'classif.featureless' on task 'pima' (iter 6/10) 
INFO  [12:46:36.511] Applying learner 'classif.featureless' on task 'pima' (iter 7/10) 
INFO  [12:46:36.542] Applying learner 'classif.featureless' on task 'pima' (iter 8/10) 
INFO  [12:46:36.558] Applying learner 'classif.featureless' on task 'pima' (iter 9/10) 
INFO  [12:46:36.589] Applying learner 'classif.featureless' on task 'pima' (iter 10/10) 
INFO  [12:46:36.605] Applying learner 'classif.rpart' on task 'pima' (iter 1/10) 
INFO  [12:46:36.651] Applying learner 'classif.rpart' on task 'pima' (iter 2/10) 
INFO  [12:46:36.698] Applying learner 'classif.rpart' on task 'pima' (iter 3/10) 
INFO  [12:46:36.729] Applying learner 'classif.rpart' on task 'pima' (iter 4/10) 
INFO  [12:46:36.839] Applying learner 'classif.rpart' on task 'pima' (iter 5/10) 
INFO  [12:46:36.870] Applying learner 'classif.rpart' on task 'pima' (iter 6/10) 
INFO  [12:46:36.917] Applying learner 'classif.rpart' on task 'pima' (iter 7/10) 
INFO  [12:46:36.963] Applying learner 'classif.rpart' on task 'pima' (iter 8/10) 
INFO  [12:46:37.010] Applying learner 'classif.rpart' on task 'pima' (iter 9/10) 
INFO  [12:46:37.073] Applying learner 'classif.rpart' on task 'pima' (iter 10/10) 
INFO  [12:46:37.104] Applying learner 'classif.featureless' on task 'sonar' (iter 1/10) 
INFO  [12:46:37.119] Applying learner 'classif.featureless' on task 'sonar' (iter 2/10) 
INFO  [12:46:37.135] Applying learner 'classif.featureless' on task 'sonar' (iter 3/10) 
INFO  [12:46:37.166] Applying learner 'classif.featureless' on task 'sonar' (iter 4/10) 
INFO  [12:46:37.182] Applying learner 'classif.featureless' on task 'sonar' (iter 5/10) 
INFO  [12:46:37.229] Applying learner 'classif.featureless' on task 'sonar' (iter 6/10) 
INFO  [12:46:37.244] Applying learner 'classif.featureless' on task 'sonar' (iter 7/10) 
INFO  [12:46:37.275] Applying learner 'classif.featureless' on task 'sonar' (iter 8/10) 
INFO  [12:46:37.291] Applying learner 'classif.featureless' on task 'sonar' (iter 9/10) 
INFO  [12:46:37.322] Applying learner 'classif.featureless' on task 'sonar' (iter 10/10) 
INFO  [12:46:37.338] Applying learner 'classif.rpart' on task 'sonar' (iter 1/10) 
INFO  [12:46:37.400] Applying learner 'classif.rpart' on task 'sonar' (iter 2/10) 
INFO  [12:46:37.478] Applying learner 'classif.rpart' on task 'sonar' (iter 3/10) 
INFO  [12:46:37.556] Applying learner 'classif.rpart' on task 'sonar' (iter 4/10) 
INFO  [12:46:37.634] Applying learner 'classif.rpart' on task 'sonar' (iter 5/10) 
INFO  [12:46:37.697] Applying learner 'classif.rpart' on task 'sonar' (iter 6/10) 
INFO  [12:46:37.775] Applying learner 'classif.rpart' on task 'sonar' (iter 7/10) 
INFO  [12:46:37.853] Applying learner 'classif.rpart' on task 'sonar' (iter 8/10) 
INFO  [12:46:37.931] Applying learner 'classif.rpart' on task 'sonar' (iter 9/10) 
INFO  [12:46:37.993] Applying learner 'classif.rpart' on task 'sonar' (iter 10/10) 
INFO  [12:46:38.055] Finished benchmark 
> 
> head(fortify(object))
Error: $ operator is invalid for atomic vectors
Execution halted