message: Unset go modules support so protobuf can be built
  Go modules can't be enabled for building protobuf. Closes
diff: /// Contains helpers for build.rs files. Includes helpers for proto compilation
  use std::path::{Path, PathBuf};
  +use std::env;
  use walkdir::WalkDir;
  // Compiles all proto files under proto root and dependent roots.
  @@ -11,6 +12,7 @@ use walkdir::WalkDir;
  // `src/a/b/c_grpc.rs`.
  pub fn compile_proto(proto_root: &str, dependent_roots: Vec<&str>, generate_client_code: bool) {
  let mut additional_includes = vec![];
  + env::remove_var("GO111MODULE");
  for dependent_root in dependent_roots {
  // First compile dependent directories
  compile_dir(
  