Hi, there is a new issue with parallell:makeCluster() that apparently only affects new version of R on MacOS. (see here)
It causes gbm to freeze when using CV. A quick fix is to pass setup_strategy="sequential" to makeCluster in gbmCluster().
Add in your code before calling gbm:
gbmCluster = function (n)
{
if (is.null(n)) {
n <- parallel::detectCores()
}
parallel::makeCluster(n, setup_strategy = "sequential")
}
assignInNamespace("gbmCluster", gbmCluster, ns="gbm")
Hope it is useful to someone ! :)