My makefile uses cargo by ripping out the cargo build information from upstream dependencies to manually run, as projects like reqwest and tokio use cargo. My demonstration was that you still would use cargo the build system rather than cargo the package manager (implying upstream registries like crates.io) over a makefile. And yes, you can use existing tools. As mentioned, systemd uses meson, though they need a python hack to get rustc working because it wasn’t working on meson upstream until 5 days ago. So yes, you can use existing tools. And as I said in another comment, for a mature project built in C, it makes sense to frankenbuild rust into the build system. But their example was purely about rust projects, I brought up makefiles to demonstrate how you can’t just slap a makefile into a rust project and it works