Problem in R: package reticulate does not work with doparallel

Question

I recently bumped into a new problem with reticulate and doparallel that I never seen before.

The following code works well with %do% (which is regular for loop) BUT NOT with %dopar% (doParallel package)

library(doParallel)
library(reticulate)

cl <- makeCluster(4)
registerDoParallel(cl)

foreach(j=1:4,.combine=rbind,.packages = "reticulate") %dopar%
{
test <- "Testing to see if dopar can recognize reticulate"
py_run_string("for i in range(len(r.test)): print(i)")
}

Here is the error message:

"Error in { : 
  task 1 failed - "RuntimeError: Evaluation error: object 'test' not found."

By default, test is an R object and when using reticulate, r.test will be recognized as an object in python py_run_string. However, the dopar created different cluster and therefore the r.test is not recognized anymore. The strange thing in here is that I have test ran inside the foreach loop and reticulate loaded for each small cluster.

Any hint would help. Thanks in advance.