// Escape attempt: malicious build.rs that tries to write a host marker file // during `cargo build`. A sandboxed build should prevent this. // // Expected behaviour in an isolated sandbox: file NOT created, build fails // or marker stays absent. // Expected behaviour on unsandboxed host: marker would appear at /tmp/pwned_build_rs. fn main() { // Attempt to write a marker file on the host. let marker = std::path::Path::new("/tmp/pwned_build_rs"); if std::fs::File::create(marker).is_ok() { // Escape succeeded: signal via stdout (cargo captures build script stdout). println!("cargo:warning=NYX_ESCAPE_SUCCESS: build.rs created /tmp/pwned_build_rs"); } else { println!("cargo:warning=BLOCKED: could not write /tmp/pwned_build_rs"); } }