for now, due to gcc-rs not being completed yet and the rustc compiler not supporting every linux architecture

There's two gcc-based compilers for Rust, gcc-rs which is part of the gcc suite and written in C++, and rustc_codegen_gcc, which is an optional backend for the existing Rust compiler written in Rust which emits an intermediate representation that GCC can understand. rustc_codegen_gcc is much closer to completion.