GraalVM R Runtime Compatibility

The GraalVM R runtime is based on GNU R and reuses the base packages. It is currently based on GNU R 4.0.3, and moves to new major versions of R as they become available and stable. GraalVM’s R runtime developers maintain an extensive set of unit tests for all aspects of the R language and the builtin functionality, and these tests are available as part of the R source code.

GraalVM’s R runtime aims to be fully compatible with GNU R, including its native interface as used by R extensions. It can install and run unmodified, complex R packages like ggplot2, Shiny, or Rcpp. As some packages rely on unspecified behaviour or implementation details of GNU R, support for packages is a work in progress, and some packages might not install successfully or work as expected.

Installing Packages

Packages can be installed using the install.packages function or the R CMD INSTALL shell command. By default, GraalVM’s R runtime uses a fixed snapshot of the CRAN repository¹. This behavior can be overridden by explicitly setting the repos argument of the install.packages function. This functionality does not interfere with the checkpoint package. If you are behind a proxy server, make sure to configure the proxy either with environment variables or using the JVM options, e.g., --vm.Djava.net.useSystemProxies=true.

The versions of some packages specifically patched for GraalVM’s R runtime can be installed using the install.fastr.packages function that downloads them from the GitHub repository. Currently, those are rJava and data.table.

Limitations

There are some limitations of the GraalVM R runtime compared to GNU R:

• Only small parts of the low-level graphics package are functional. However, the grid package is supported and R can install and run packages based on it, like ggplot2. Support for the graphics package in R is planned for future releases.
• Encoding of character vectors: related builtins (e.g., Encoding) are available, but do not execute any useful code. Character vectors are represented as Java Strings and therefore encoded in the UTF-16 format. GraalVM’s R runtime will add support for encoding in future releases.
• Some parts of the native API (e.g., DATAPTR) expose implementation details that are hard to emulate for alternative implementations of R. These are implemented as needed while testing the GraalVM R runtime with various CRAN packages.

¹ More technically, GraalVM’s R runtime uses a fixed MRAN URL from $R_HOME/etc/DEFAULT_CRAN_MIRROR, which is a snapshot of the CRAN repository as it was visible at a given date from the URL string.