[R-pkg-devel] "Connections left open" Error

Hi,

I submitted a package to CRAN, but it keeps failing a particular check for
Windows. This error shows up when I check my code examples.

Error: connections left open:

        <-CRANwin.fb05.statistik.uni-dortmund.de:11602
<http://cranwin.fb05.statistik.uni-dortmund.de:11602/> (sockconn)
        <-CRANwin.fb05.statistik.uni-dortmund.de:11602
<http://cranwin.fb05.statistik.uni-dortmund.de:11602/> (sockconn)
Execution halted

For context, my code example does the following.

suppressWarnings(require(doParallel))

registerDoParallel(cores = 2)

# Some code examples that use foreach and %dopar%



stopImplicitCluster()


Other contextual information:

   - I already import doParallel in the DESCRIPTION file.
   - My package passes all checks on the Linux machine.

I have read elsewhere (e.g., this thread
<https://github.com/HenrikBengtsson/future/issues/327>) that examples with
parallelization lead to this error. However stopImplicitCluster() does not
seem to fix it.

Could someone familiar with this please troubleshoot? Thank you.

Alan