Importing definitions fails because of incorrect package path

[jpoz]

When I import some of google's proto definitions the generated code imports a package that does not exist.

Example:

syntax = "proto3";

import "google/protobuf/timestamp.proto";

package bar;

message Foo {
  google.protobuf.Timestamp start = 1;
  google.protobuf.Timestamp finish = 2;
}

Generated code:

package bar

import proto "github.com/golang/protobuf/proto"
import google_protobuf "google/protobuf"

...

The import of google_protobuf fails.

• Should I be building the google_protobuf package and adding it manually to my GOPATH?
• Is there a directive I'm missing to tell the protoc generator to build dependencies?
• Bug in golang/protobuf? Where would i start looking to add a fix?

[dsymonds]

protoc-gen-go needs to be told what import path to generate for packages that it can't guess.

The simplest option is to run protoc from a directory where the subdir holding the .proto file will be the import path (e.g. in $GOPATH/src).

The next best option is to pass one or more M parameters to specify the mapping of .proto file to import path. See protoc-gen-go/plugin/Makefile in this repo for an example of that.