cran: CRAN compliant extendr packages

In extendr/rextendr: Call Rust Code from R using the 'extendr' Crate

CRAN compliant extendr packages

Description

R packages developed using extendr are not immediately ready to be published to CRAN. The extendr package template ensures that CRAN publication is (farily) painless.

CRAN requirements

In order to publish a Rust based package on CRAN it must meet certain requirements. These are:

• Rust dependencies are vendored

• The package is compiled offline

• the DESCRIPTION file's SystemRequirements field contains ⁠Cargo (Rust's package manager), rustc⁠

The extendr templates handle all of this except vendoring dependencies. This must be done prior to publication using vendor_pkgs().

In addition, it is important to make sure that CRAN maintainers are aware that the package they are checking contains Rust code. Depending on which and how many crates are used as a dependencies the vendor.tar.xz will be larger than a few megabytes. If a built package is larger than 5mbs CRAN may reject the submission.

To prevent rejection make a note in your cran-comments.md file (create one using usethis::use_cran_comments()) along the lines of "The package tarball is 6mb because Rust dependencies are vendored within src/rust/vendor.tar.xz which is 5.9mb."

extendr/rextendr documentation built on April 5, 2025, 1:53 a.m.