title: What does the future package mean when it says mcapply is known to be unstable?
body: <p>I'm trying to understand the quote below from the future package.  What is meant by &quot;known to be unstable&quot;?  Does that mean it mcapply might crash, or are the result from mcapply not reliable?</p>
  <p>&quot;Parallelization via multi-threaded processing (done in native code by some packages and external libraries) while at the same time using forked (aka &quot;multicore&quot;) parallel processing is known to unstable. Note that this is not only true when using plan(multicore) but also when using, for instance, mclapply() of the parallel package.&quot;</p>