[R-pkg-devel] Is there an Rtools40 changelog?

[Jeroen Ooms]

On Sun, May 10, 2020 at 11:31 PM James Lamb <jaylamb20 using gmail.com> wrote:
>
> Hello,
>
> I am a maintainer on the LightGBM project, focused on that project's R
> package. The R package is not available on CRAN yet (we are working on it),
> so for now our users must build it from source.
>
> The package includes compilation of a C++ library, and we link to R.dll /
> R.so to use R-provided functions like Rprintf.
>
> With the release of R4.0 and Rtools40, we recently received reports from
> our users that they are unable to build our package on Windows systems with
> R 4.0 and Rtools 4.0 (https://github.com/microsoft/LightGBM/issues/3064).
>
> After some investigation, I've learned that the following changes in
> Rtools40 (relative to Rtools35) broke our installation process:
>
>    - *gendef.exe* was removed
>    - *mingw32-make.exe* was removed
>    - paths like "mingw_64/bin" were changed to "mingw64/bin"
>

Some utilities that were previously bundled with all rtools
installations can now be installed with the package manager.

To install gendef use:

     pacman -S mingw-w64-{i686,x86_64}-tools

To install mingw32-make.exe use:

      pacman -S mingw-w64-{i686,x86_64}-make

To install both of the at once you can use:

      pacman -S mingw-w64-{i686,x86_64}-{tools,make}

Note that it's often better to use 'make.exe' which is included with
all rtools installations instead of mingw32-make.exe.

These changes were a result of switching to an msys2 based toolchain.
The default rtools40 installer only includes the things needed to
build CRAN packages or base-R. Extra stuff such as system libraries,
debuggers, cmake, etc, are all optionally available via the package
manager.