During development it can be very handy to have cargo automatically recompile the code on changes.
This can be accomplished very easily by using
cargo watch -x 'run --bin app'
An old version of this page recommended using a combination of systemfd and listenfd, but this has
many gotchas and was difficult to integrate properly, especially when part of a broader development
workflow. We consider
cargo-watch to be sufficient for auto-reloading purposes.