error in caret.cv <- train(Survived

[Georgitanev]

I've closed the whole Rstudio and run it again and the same error appearing (all packages where launched)
#install.packages(c("e1071", "caret", "doSNOW", "ipred", "xgboost"))
Any Idea, why I have this error?

caret.cv <- train(Survived ~ .,

•               data = titanic.train,
  

•               method = "xgbTree",
  

•               tuneGrid = tune.grid,
  

•               trControl = train.control)
  

Error in e$fun(obj, substitute(ex), parent.frame(), e$data) :
unable to find variable "optimismBoot"

[TheTS]

There is a bug in the latest caret build on CRAN that causes this error when parallel processing. It is fixed in the dev version, but not yet released on CRAN.

topepo/caret#706

To fix, install dev build directly from github:

devtools::install_github('topepo/caret/pkg/caret')