error building opentelemetry-proto - cargo raze vs crates_universe?

specifically on https://bazelbuild.github.io/rules_rust/rust_proto.html it has

```
load("@rules_rust//proto:toolchain.bzl", "rust_proto_toolchain")

rust_proto_toolchain(
name = "proto-toolchain-impl",
# Path to the protobuf compiler.
protoc = "@com_google_protobuf//:protoc",
# Protobuf compiler plugin to generate rust gRPC stubs.
grpc_plugin = "//cargo_raze/remote:cargo_bin_protoc_gen_rust_grpc",
# Protobuf compiler plugin to generate rust protobuf stubs.
proto_plugin = "//cargo_raze/remote:cargo_bin_protoc_gen_rust",
)

toolchain(
name = "proto-toolchain",
toolchain = ":proto-toolchain-impl",
toolchain_type = "@rules_rust//proto:toolchain_type",
)

```

They don't error as such, or perhaps I'm not using them correctly; however neither do crates like `opentelemetry-proto` build correctly.