Using Rtools40 on Windows

Starting with R 4.0.0 (released April 2020), R for Windows uses a brand new toolchain bundle called rtools40.

This version of Rtools upgrades the mingw-w64 gcc toolchains to version 8.3.0, and introduces a new build system based on msys2, which makes easier to build and maintain R itself as well as the system libraries needed by R packages on Windows. For more information about the latter, follow the links at the bottom of this document.

This documentation is about rtools40, the current version used for R 4.0.0 and newer. For information about previous versions of Rtools that can be used with R 3.6.3 or older, please visit this page.

Installing Rtools40

Note that rtools40 is only needed build R packages with C/C++/Fortran code from source. By default, R for Windows installs the precompiled “binary packages” from CRAN, for which you do not need rtools!

To use rtools40, download the installer from CRAN:

On Windows 64-bit: rtools40-x86_64.exe (recommended: includes both i386 and x64 compilers)
On Windows 32-bit: rtools40-i686.exe (i386 compilers only)

Note for RStudio users: please check you are using the latest version of RStudio (at least 1.2.5042) to work with rtools40.

Putting Rtools on the PATH

After installation is complete, you need to perform one more step to be able to compile R packages: you need to put the location of the Rtools make utilities (bash, make, etc) on the PATH. The easiest way to do so is create a text file .Renviron in your Documents folder which contains the following line:

PATH="${RTOOLS40_HOME}\usr\bin;${PATH}"

You can do this with a text editor, or you can even do it from R like so:

writeLines('PATH="${RTOOLS40_HOME}\\usr\\bin;${PATH}"', con = "~/.Renviron")

Now restart R, and verify that make can be found, which should show the path to your Rtools installation.

Sys.which("make")
## "C:\\rtools40\\usr\\bin\\make.exe"

If this works, you can try to install an R package from source:

install.packages("jsonlite", type = "source")

If this succeeds, you’re good to go! See the links below to learn more about rtools40 and the Windows build infrastructure.

Further Documentation

More documentation about using rtools40 for R users and package authors:

Using pacman: the new rtools package manager to build and install C/C++ system libraries.
Installing R packages: Some older R packages that need extra help to compile.
FAQ: Common questions about Rtools40 and R on Windows.

Advanced information about building R base and building system libraries:

r-base: Scripts for building R for Windows using rtools40.
rtools-packages: Toolchains and static libraries for rtools40 (GCC 8+)
rtools-backports: Backported C/C++ libraries for the gcc-4.9.3 legacy toolchain (for R 3.3 - 3.6)
rtools-installer: Builds the rtools40 installer bundle.