[Rd] tempdir() may be deleted during long-running R session

[Jeroen Ooms]

On Tue, Apr 25, 2017 at 1:00 PM, Martin Maechler
<maechler at stat.math.ethz.ch> wrote:
> As I've found it is not at all hard to add an option which
> checks the existence and if the directory is no longer "valid",
> tries to recreate it (and if it fails doing that it calls the
> famous R_Suicide(), as it does when R starts up and tempdir()
> cannot be initialized correctly).

Perhaps this can also fix the problem with mcparallel deleting the
tempdir() when one of its children dies:

  file.exists(tempdir()) #TRUE
  parallel::mcparallel(q('no'))
  file.exists(tempdir()) # FALSE