create rust workspace (#32014)

rust/sglang-grpc/build.rs

@@ -1,4 +1,16 @@
 fn main() -> Result<(), Box<dyn std::error::Error>> {
+    // Prefer an explicitly configured protoc; otherwise use the vendored
+    // binary so builds (including `cargo clippy` and the pre-commit hook on
+    // machines/CI runners without protobuf installed) are self-contained.
+    // protoc_bin_path() errs on platforms the vendored crate doesn't cover;
+    // those fall back to prost-build's own lookup of `protoc` on PATH.
+    if std::env::var_os("PROTOC").is_none()
+        && let Ok(vendored) = protoc_bin_vendored::protoc_bin_path()
+    {
+        // SAFETY: build scripts are single-threaded at this point.
+        unsafe { std::env::set_var("PROTOC", vendored) };
+    }
+
     let proto_path = "../../proto/sglang/runtime/v1/sglang.proto";
 
     tonic_build::configure()