An alternative to the Mozilla nixpkgs overlay for working with the binary Rust releases on Nix{,OS}.
export NIX_PATH=$NIX_PATH:rust=https://github.com/arcnmx/nixexprs-rust/archive/master.tar.gz
nix-shell '<rust>' -A nightly.cargo --run "cargo --version"Currently everything is undocumented, so dig through the source or check out the cross-compiling example.