cargo watch
In case you are working on a server project (e.g. hyper, iron, etc) that keeps running and you need it to be restarted when files change, you can use cargo watch. Install:
cargo install cargo-watch
And then run:
cargo watch -x run
And to watch changes in only the src folder and clear the console use:
cargo watch -c -w src -x run
See the cargo-watch README for more examples.
watchexec
Alternatively, you can use watchexec. Install it:
cargo install watchexec-cli
And then use it like this:
watchexec -r cargo run