Question: I'm trying to use `google/protobuf/timestamp.proto` in with gRPC plugin and Go. This is how I run `protoc`:

```
protoc -I  ./   ./*.proto --go_out=plugins=grpc:.

```

And this is my `.proto`:

```
#domain.proto
syntax = "proto3";
option java_multiple_files = true;
option java_package = "com.viant.xyz";
option java_outer_classname = "domain";

import "google/protobuf/timestamp.proto";

message Foo {
    Timestamp modifiedTime = 1;
    ...
}

```

I'm seeing the following errors:

```
domain.proto: Import "google/protobuf/timestamp.proto" was not found or had errors.
domain.proto:44:5: "Timestamp" is not defined.

```

Am I missing something, or this is not yet supported?

Answer: 
Add `/usr/local/include` to include paths to use `/usr/local/include/google/api/timestamp.proto`:

```
protoc -I/usr/local/include -I. --go_out=plugins=grpc:. *.proto

```

As you can see in `timestamp.proto`, `Timestamp` exists in package `google.protobuf`, so you have to modify to use `Timestamp` like this:

```
message Foo {
    google.protobuf.Timestamp modifiedTime = 1;
    ...
}

```
In windows, clone the repository:[protobuf](https://github.com/protocolbuffers/protobuf).

And run the command

```
protoc -I=$SRC_DIR -I=$YOUR_CLONE_LOCATION/protobuf/src --go_out=$DST_DIR $SRC_DIR/$SRC_FILE

```