As of today cargo-clone is published on crates.io. It can be used to fetch source code of any project published on crates.io. I would be glad to receive feedback, PR requests are also welcome!
Any thoughts around cloning the git repo for crates that have a repository specified in Cargo.toml? That would always be what I want. cargo clone --head? which would skip the download from crates.io and clone directly from git.
cargo clone --head