---
-title: "carego careful: run your Rust code with extra careful debug checking"
+title: "cargo careful: run your Rust code with extra careful debug checking"
categories: rust
+reddit: /rust/comments/xogayv/cargo_careful_run_your_rust_code_with_extra/
---
Did you know that the standard library is full of useful checks that users never get to see?
[`cargo careful`](https://github.com/RalfJung/cargo-careful) is here to close this gap:
when invoked the first time, it builds a standard library with debug assertions from source, and then runs your program or test suite with that standard library.
-Installing `cargo careful` is as easy as `cargo install cargo-careful`, and then you can do `cargo careful run`/`cargo careful test` to execute your binary crates and test suites with an extra amount of debug checking.
+Installing `cargo careful` is as easy as `cargo install cargo-careful`, and then you can do `cargo +nightly careful run`/`cargo +nightly careful test` to execute your binary crates and test suites with an extra amount of debug checking.
This will naturally be slower than a regular debug or release build, but it is *much* faster than executing your program in [Miri](https://github.com/rust-lang/miri) and still helps find some Undefined Behavior.
Unlike Miri, it is fully FFI-compatible (though the code behind the FFI barrier is completely unchecked).
Meanwhile, if you have some `unsafe` code that for one reason or another you cannot test with Miri, give [`cargo careful`] a try and let me know how it is doing. :)
[`cargo careful`]: https://github.com/RalfJung/cargo-careful
+
+*By the way, I am soon [starting as a professor at ETH Zürich]({% post_url 2022-08-16-eth %}), so if you are interested in working with me on programming language theory as a master student, PhD student, or post-doc, then please [reach out](https://research.ralfj.de/contact.html)!*