"If you implement boundaries and nobody is around to push them, do they even exist?". Have you ever wondered how your sandbox looks like from the inside? Tempted to test if you can escape it, if only you had a shell to give it a try? boxxy is a library that can be linked into a debug build of an existing program and drop you into an interactive shell. From there you can step through various stages of your sandbox and verify it actually contains™. Just put a dev-dependencies in your Cargo.toml and copy examples/boxxy.rs to your examples/ folder. Modify to include your sandbox.