Regardless of which operating system you use, we recommend using rustup to install and maintain your Rust toolchain. On Linux and OS X, you simply run the following command in a shell:

curl --proto '=https' --tlsv1.2 -sSf | sh

No further action should be needed.

On Windows, things are a little more involved. First download rustup‑init.exe from the rustup site and run it, following the on-screen instructions. Rust may require installation of VC++ build tools (more instructions can be found here). Once installed, execute the following rustup commands:

rustup default stable-x86_64-pc-windows-msvc
rustup target add x86_64-pc-windows-gnu
rustup target add i686-pc-windows-gnu

Second, install Rtools. The latest installer is available on CRAN. Alternatively, Rtools can be installed using chocolatey:

choco install rtools -y

Finally, make sure that environment variables are set up correctly. R_HOME should point to the R folder, e.g. C:\Program Files\R\R-4.1.0 (be careful with spaces in the path). RTOOLS40_HOME should point to the Rtools folder (usually set up automatically by the installer), which is C:\rtools40 by default. PATH should contain paths to %R_HOME%\bin and %RTOOLS40_HOME%\usr\bin, as well as cargo, which is found at %USERPROFILE%\.cargo\bin if installed using rustup-init.exe.