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

> ### Name: future_by
> ### Title: Apply a Function to a Data Frame Split by Factors via Futures
> ### Aliases: future_by
> 
> ### ** Examples
> 
> ## ---------------------------------------------------------
> ## by()
> ## ---------------------------------------------------------
> library(datasets) ## warpbreaks
> library(stats)    ## lm()
> 
> y0 <- by(warpbreaks, warpbreaks[,"tension"],
+          function(x) lm(breaks ~ wool, data = x))
> 
> plan(multisession)
Error in get(name, envir = asNamespace(pkg), inherits = FALSE) : 
  object '.slaveRSOCK' not found
Calls: ::: -> get
Execution halted
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  NAs introduced by coercion
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  NAs introduced by coercion
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  NAs introduced by coercion
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  NAs introduced by coercion
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  NAs introduced by coercion
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  NAs introduced by coercion
Warning in doTryCatch(return(expr), name, parentenv, handler) :
  NAs introduced by coercion
Error in socketConnection("localhost", port = port, server = TRUE, blocking = TRUE,  : 
  Failed to launch and connect to R worker on local machine 'localhost' from local machine 'CRANWIN'.
 * The error produced by socketConnection() was: 'reached elapsed time limit' (which suggests that the connection timeout of 120 seconds (argument 'connectTimeout') kicked in)
 * The localhost socket connection that failed to connect to the R worker used port 37400 using a communication timeout of 120 seconds and a connection timeout of 120 seconds.
 * Worker launch call: "D:/RCompile/recent/R/bin/x64/Rscript" --default-packages=datasets,utils,grDevices,graphics,stats,methods -e "#label=future.apply-Ex.R:177736:CRANWIN:CRAN" -e "try(suppressWarnings(cat(Sys.getpid(),file=\"D:/temp/RtmpCidYe2/future.parent=177736.2b6481f7754b0.pid\")), silent = TRUE)" -e "parallel:::.slaveRSOCK()" MASTER=localhost PORT=37400 OUT=/dev/null TIMEOUT=120 XDR=TRUE.
 * Worker (PID 179372) was successfully killed: TRUE
 * Troubleshooting suggestions:
   - Suggestion #1: Set 'verbose=TRUE' to see more details.
   - Suggestion #2: On Windows, output from worker when using 'outfile=NULL' is only visible when running R from a terminal (not a GUI).
Calls: plan ... tryCatchList -> tryCatchOne -> <Anonymous> -> <Anonymous>
Execution halted