The default nested plan is always sequential, regardless of R_FUTURE_PLAN

Author: HenrikBengtsson

R/backend_api-ClusterRegistry.R

@@ -47,6 +47,11 @@ ClusterRegistry <- local({
 
 .makeCluster <- function(workers, ...) {
   if (length(workers) == 0L) return(NULL)
+  oenv <- Sys.getenv("R_FUTURE_PLAN", NA_character_)
+  Sys.unsetenv("R_FUTURE_PLAN")
+  on.exit({
+    if (!is.na(oenv)) Sys.setenv(R_FUTURE_PLAN = oenv)
+  })
   cl <- makeClusterPSOCK(workers, ...)
   cl <- addCovrLibPath(cl)
   cl

R/backend_api-Future-class.R

@@ -783,8 +783,7 @@ getFutureContext <- function(future, mc.cores = NULL, local = TRUE, ..., debug =
   ## Use default future strategy + identify packages needed by the backend
   if (length(strategiesR) == 0L) {
     if (debug) mdebug("Packages needed by future strategies (n = 0): <none>")
-    strategiesR <- getOption("future.plan")
-    if (is.null(strategiesR)) strategiesR <- sequential
+    strategiesR <- sequential
     backendPackages <- c("future")
   } else {
     ## Identify package namespaces needed for strategies