Cargo's new index protocol will be available starting in Rust 1.68, which will be released on 2023-03-09. This new "sparse" protocol should usually provide a significant performance improvement when accessing crates.io.
We would like your help in testing this new feature and infrastructure.
If you use beta (1.68) or nightly-2023-01-21 or newer, set the environment variable
CARGO_REGISTRIES_CRATES_IO_PROTOCOL=sparse, or edit your
.cargo/config.toml file to add:
[registries.crates-io] protocol = "sparse"
We would like to hear reports on your experience. If you run into a problem, please open an issue. If you would like to post general feedback, feel free to leave a message here.
More information can be found in this blog post: Help test Cargo's new index protocol | Inside Rust Blog