wtf is meta-rust-bin?

meta-rust-bin lets you add the Rust programming language to devices built with Yocto, a system for creating custom Linux distributions for embedded hardware like routers, sensors, or industrial controllers. Instead of compiling the Rust toolchain from source code, which can take a long time, it downloads ready-made, pre-built binaries straight from the official Rust project. In practice, if you are building a Linux image for a piece of hardware and want to include a program written in Rust, you point your build recipe at the Rust source code, inherit a class called cargo_bin, and the layer handles the rest. It pulls in the right Rust compiler and package manager, compiles your program, and installs it into the device image. The layer supports common processor architectures (x86 and ARM, both 32-bit and 64-bit) and whatever Linux targets Rust itself supports. This would appeal to embedded engineers building products on custom hardware who want to write their firmware or system utilities in Rust. For example, if you are making a smart home hub or a factory controller running a tailored Linux OS, and your team writes Rust code, this layer bridges the gap between Rust and Yocto's build system. You can also toggle specific Cargo features, meaning you can compile different capabilities into your program depending on whether it is destined for real hardware or a developer's laptop. The notable tradeoff is speed versus flexibility. Because it uses pre-built binaries rather than compiling Rust from source, new Rust versions become available almost immediately and builds are much faster. The downside is that you are limited to whatever architectures and options the official Rust team provides, and the pre-built standard libraries might be slightly less optimized than ones you compiled yourself for your specific target. The layer also notes that running Rust directly on the target device (rather than cross-compiling from a build machine) is untested and probably will not work yet.