Crabrix Puts a Rust Compiler on Your iPhone

Field notes

Crabrix packages a pinned WASI build of rustc inside a Swift WebAssembly interpreter, allowing the app to perform type checking, borrow checking, dependency compilation, and diagnostic reporting locally. Its package flow includes sparse-index resolution, SemVer and feature unification, SHA-256 verification, Cargo.lock generation, and cached offline rebuilds. The bundled learning material contains 83 lessons across six courses, alongside 20 projects and practice modes. The site explicitly marks procedural macros, build scripts, and native C-library dependencies as limitations.