Running examples in ‘drake-Ex.R’ failed
The error most likely occurred in:

> base::assign(".ptime", proc.time(), pos = "CheckExEnv")
> ### Name: evaluate_plan
> ### Title: Use wildcard templating to create a workflow plan data frame
> ###   from a template data frame.
> ### Aliases: evaluate_plan
> 
> ### ** Examples
> 
> # Create the part of the workflow plan for the datasets.
> datasets <- drake_plan(
+   small = simulate(5),
+   large = simulate(50))
> # Create a template workflow plan for the analyses.
> methods <- drake_plan(
+   regression1 = reg1(dataset__),
+   regression2 = reg2(dataset__))
> # Evaluate the wildcards in the template
> # to produce the actual part of the workflow plan
> # that encodes the analyses of the datasets.
> # Create one analysis for each combination of dataset and method.
> evaluate_plan(methods, wildcard = "dataset__",
+   values = datasets$target)
# A tibble: 4 x 2
  target            command    
* <chr>             <chr>      
1 regression1_small reg1(small)
2 regression1_large reg1(large)
3 regression2_small reg2(small)
4 regression2_large reg2(large)
> # Only choose some combinations of dataset and analysis method.
> ans <- evaluate_plan(methods, wildcard = "dataset__",
+   values = datasets$target, expand = FALSE)
> ans
# A tibble: 2 x 2
  target      command    
* <chr>       <chr>      
1 regression1 reg1(small)
2 regression2 reg2(large)
> # For the complete workflow plan, row bind the pieces together.
> my_plan <- rbind(datasets, ans)
> my_plan
# A tibble: 4 x 2
  target      command     
  <chr>       <chr>       
1 small       simulate(5) 
2 large       simulate(50)
3 regression1 reg1(small) 
4 regression2 reg2(large) 
> # Workflow plans can have multiple wildcards.
> # Each combination of wildcard values will be used
> # Except when expand is FALSE.
> x <- drake_plan(draws = rnorm(mean = Mean, sd = Sd))
> evaluate_plan(x, rules = list(Mean = 1:3, Sd = c(1, 10)))
# A tibble: 6 x 2
  target     command                 
* <chr>      <chr>                   
1 draws_1_1  rnorm(mean = 1, sd = 1) 
2 draws_1_10 rnorm(mean = 1, sd = 10)
3 draws_2_1  rnorm(mean = 2, sd = 1) 
4 draws_2_10 rnorm(mean = 2, sd = 10)
5 draws_3_1  rnorm(mean = 3, sd = 1) 
6 draws_3_10 rnorm(mean = 3, sd = 10)
> # You can use wildcards on columns other than "command"
> evaluate_plan(
+   drake_plan(
+     x = target("always", cpu = "any"),
+     y = target("any", cpu = "always"),
+     z = target("any", cpu = "any"),
+     strings_in_dots = "literals"
+   ),
+   rules = list(always = 1:2),
+   columns = c("command", "cpu")
+ )
# A tibble: 5 x 3
  target command cpu  
* <chr>  <chr>   <chr>
1 x_1    1       any  
2 x_2    2       any  
3 y_1    any     1    
4 y_2    any     2    
5 z      any     any  
> # With the `trace` argument,
> # you can generate columns that show how the wildcards
> # were evaluated.
> plan <- drake_plan(x = rnorm(n__), y = rexp(n__))
> plan <- evaluate_plan(plan, wildcard = "n__", values = 1:2, trace = TRUE)
> print(plan)
# A tibble: 4 x 4
  target command  n__   n___from
* <chr>  <chr>    <chr> <chr>   
1 x_1    rnorm(1) 1     x       
2 x_2    rnorm(2) 2     x       
3 y_1    rexp(1)  1     y       
4 y_2    rexp(2)  2     y       
> # With the `trace` argument,
> # you can generate columns that show how the wildcards
> # were evaluated. Then you can visualize the wildcard groups
> # as clusters.
> plan <- drake_plan(x = rnorm(n__), y = rexp(n__))
> plan <- evaluate_plan(plan, wildcard = "n__", values = 1:2, trace = TRUE)
> print(plan)
# A tibble: 4 x 4
  target command  n__   n___from
* <chr>  <chr>    <chr> <chr>   
1 x_1    rnorm(1) 1     x       
2 x_2    rnorm(2) 2     x       
3 y_1    rexp(1)  1     y       
4 y_2    rexp(2)  2     y       
> cache <- storr::storr_environment()
> config <- drake_config(plan, cache = cache)
> vis_drake_graph(config, group = "n__", clusters = "1")
Error in `[<-.data.frame`(`*tmp*`, is_file(nodes$id), "type", value = "file") : 
  replacement has 1 row, data has 0
Calls: vis_drake_graph ... with.default -> eval -> eval -> [<- -> [<-.data.frame
Execution halted