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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.