lmao perhaps

packages/linux-cachyos/lib/rust-pkgs.nix

@@ -0,0 +1,9 @@
+# Resolve the Rust toolchain packages needed for CONFIG_RUST=y kernel builds.
+# Uses buildPackages so cross-compilation works correctly (the compiler runs on
+# the build machine but produces code for the host/target).
+{ pkgs, ... }:
+{
+  rustc = pkgs.buildPackages.rustc-unwrapped;
+  rustBindgen = pkgs.buildPackages.rust-bindgen-unwrapped;
+  rustLibSrc = pkgs.buildPackages.rustPlatform.rustLibSrc;
+}