protoc_extra_arg not passed through

[jrcichra]

Context on the situation: I have a Starlink that provides a .protoset file from this command:

grpcurl -plaintext -protoset-out dish.protoset 192.168.100.1:9200 describe SpaceX.API.Device.Device

...and I would like to interact with the Starlink gRPC through Rust through the protoset it provides.

With cargo install protobuf-codegen, I can generate device.rs and mod.rs files no problem:

protoc --rust_out=. --descriptor_set_in=protos/dish.protoset spacex/api/device/device.proto

I'd like to do this within build.rs - something like:

fn main() -> Result<(), Box<dyn std::error::Error>> {
    protobuf_codegen::Codegen::new()
        // Use `protoc` parser, optional.
        .protoc()
        // Use `protoc-bin-vendored` bundled protoc command, optional.
        .protoc_path(&protoc_bin_vendored::protoc_bin_path().unwrap())
        // All inputs and imports from the inputs must reside in `includes` directories.
        // Inputs must reside in some of include paths.
        .protoc_extra_arg("--descriptor_set_in=protos/dish.protoset")
        .includes(&["spacex/api/device"])
        .input("spacex/api/device/device.proto")
        // Specify output directory relative to Cargo output directory.
        .cargo_out_dir("protoout")
        .run_from_script();

    Ok(())
}

However, doing so yields this output:

   Compiling rusty-space-dish v0.1.0 (/home/justin/git/rusty-space-dish)
error: failed to run custom build command for `rusty-space-dish v0.1.0 (/home/justin/git/rusty-space-dish)`

Caused by:
  process didn't exit successfully: `/home/justin/git/rusty-space-dish/target/debug/build/rusty-space-dish-ecceed33977cb51e/build-script-build` (exit status: 1)
  --- stderr
  spacex/api/device: warning: directory does not exist.
  Could not make proto path relative: spacex/api/device/device.proto: No such file or directory
  codegen failed: parse and typecheck

  Caused by:
      0: using protoc parser
      1: protoc command "/home/justin/.cargo/registry/src/github.com-1ecc6299db9ec823/protoc-bin-vendored-linux-x86_64-3.0.0/bin/protoc" "-Ispacex/api/device" "--descriptor_set_out=/tmp/protobuf-parseHkQe9P/descriptor.pbbin" "--include_imports" "spacex/api/device/device.proto" exited with non-zero code

My extra arg to protoc was not passed in according to cause #1.