I think maybe they were confused by this text (which I agree has nothing to do with Rust itself breaking):
> With the release of Apache Arrow 3.0.0 there are many breaking changes in the Rust implementation and as a result it has been necessary to comment out much of the code in this repository and gradually get each Rust module working again with the 3.0.0 release.
> With the release of Apache Arrow 3.0.0 there are many breaking changes in the Rust implementation and as a result it has been necessary to comment out much of the code in this repository and gradually get each Rust module working again with the 3.0.0 release.