Running examples in 'arrow-Ex.R' failed
The error most likely occurred in:

> ### Name: open_dataset
> ### Title: Open a multi-file dataset
> ### Aliases: open_dataset
> 
> ### ** Examples
> 
> ## Don't show: 
> if (arrow_with_dataset() & arrow_with_parquet() ) (if (getRversion() >= "3.4") withAutoprint else force)({ # examplesIf
+ ## End(Don't show)
+ # Set up directory for examples
+ tf <- tempfile()
+ dir.create(tf)
+ on.exit(unlink(tf))
+ 
+ data <- dplyr::group_by(mtcars, cyl)
+ write_dataset(data, tf)
+ 
+ # You can specify a directory containing the files for your dataset and
+ # open_dataset will scan all files in your directory.
+ open_dataset(tf)
+ 
+ # You can also supply a vector of paths
+ open_dataset(c(file.path(tf, "cyl=4/part-1.parquet"), file.path(tf,"cyl=8/part-2.parquet")))
+ 
+ ## You must specify the file format if using a format other than parquet.
+ tf2 <- tempfile()
+ dir.create(tf2)
+ on.exit(unlink(tf2))
+ write_dataset(data, tf2, format = "ipc")
+ # This line will results in errors when you try to work with the data
+ ## Not run: open_dataset(tf2)
+ # This line will work
+ open_dataset(tf2, format = "ipc") 
+ 
+ ## You can specify file partitioning to include it as a field in your dataset
+ # Create a temporary directory and write example dataset
+ tf3 <- tempfile()
+ dir.create(tf3)
+ on.exit(unlink(tf3))
+ write_dataset(airquality, tf3, partitioning = c("Month", "Day"), hive_style = FALSE)
+ 
+ # View files - you can see the partitioning means that files have been written 
+ # to folders based on Month/Day values
+ list.files(tf3, recursive = TRUE)
+ 
+ # With no partitioning specified, dataset contains all files but doesn't include
+ # directory names as field names
+ open_dataset(tf3)
+ 
+ # Now that partitioning has been specified, your dataset contains columns for Month and Day
+ open_dataset(tf3, partitioning = c("Month", "Day"))
+ 
+ # If you want to specify the data types for your fields, you can pass in a Schema
+ open_dataset(tf3, partitioning = schema(Month = int8(), Day = int8()))
+ ## Don't show: 
+ }) # examplesIf
> tf <- tempfile()
> dir.create(tf)
> on.exit(unlink(tf))
> data <- dplyr::group_by(mtcars, cyl)
Error in loadNamespace(x) : there is no package called 'dplyr'
Calls: <Anonymous> ... loadNamespace -> withRestarts -> withOneRestart -> doWithOneRestart
Execution halted