CRAN's Rust versions

CRAN does not coordinate versions of Rust across build machines, so it can be challenging to ensure your package builds on any CRAN machine. The only sure fire way to do that is to ensure that your package builds under the lowest version of Rust currently supported by a CRAN build machine, that being the minimal supported Rust version (or MSRV) on CRAN. That includes your package’s Rust dependencies, too. Any crate or feature you list in your manifest must also fall under CRAN’s MSRV.

The below table reports CRAN versions per check flavor based on the check results of the extendr package {fio}.

CRAN’s MSRV is 1.91.1.