[R] Can't rsync extsoft/3.6 when compiling R 3.6

[Jeroen Ooms]

On Thu, May 2, 2019 at 9:36 AM Martin Maechler
<maechler using stat.math.ethz.ch> wrote:
>
> >>>>> Shuguang Sun
> >>>>>     on Thu, 2 May 2019 12:57:37 +0800 writes:
>
>     > Hi all,
>     > When I try to compile R 3.6 in windows 10 in Rtools35, it raised the error message:
>     > --8<---------------cut here---------------start------------->8---
>     > make rsync-extsoft
>     > (mkdir -p ../../extsoft; \
>     > cd ../../extsoft; \
>     > rsync --timeout=60 -rcvp --delete cran.r-project.org::CRAN/bin/windows/extsoft/3.6/ . )
>     > receiving incremental file list
>     > rsync: change_dir "/bin/windows/extsoft/3.6" (in CRAN) failed: No such file or directory (2)
>     > --8<---------------cut here---------------end--------------->8---
>
>     > There is no "windows/extsoft/3.6/" and only up to 3.5.
>
>     > Best Regards,
>     > Shuguang Sun
>
> Indeed.
> If you look at this FTP directory in a capabable browser (such
> as Emacs), you see
>
>     Dec 22 2014  3.2
>     Jun 16 2016  3.3
>     Jul  6 2016  3.4 -> 3.3
>     May  8 2017  3.5 -> 3.3
>
> So it seems the CRAN team (or the R Core release master?) forgot
> to make that symbolic link there.

I think that might be my responsibility (not entirely sure honestly).
I'll add that directory and include the current versions of the libs
we use to build the official r-base on Windows.