Steps to reproduce, once you have cargo and rustc from Debian stable repositories: cargo init && cargo add clap && cargo run. The following happens:
error: package `anstream v0.6.4` cannot be built because it requires rustc 1.70.0 or newer, while the currently active rustc version is 1.63.0
Either upgrade to rustc 1.70.0 or newer, or use
cargo update -p anstream@0.6.4 --precise ver
where `ver` is the latest version of `anstream` supporting rustc 1.63.0