title: file not found / unable to import package
body: <p>I have been following a gRPC tutorial, this works perfectly fine. The problems start when I try to add <a href="https://github.com/grpc-ecosystem/grpc-gateway" rel="nofollow noreferrer">https://github.com/grpc-ecosystem/grpc-gateway</a> to my project. I use the commands they give you:</p>
  
  <pre><code>go get -u github.com/grpc-ecosystem/grpc-gateway/protoc-gen-grpc-gateway
  go get -u github.com/grpc-ecosystem/grpc-gateway/protoc-gen-swagger
  go get -u github.com/golang/protobuf/protoc-gen-go
  </code></pre>
  
  <p>and I import the package in my proto:</p>
  
  <pre><code>import "google/api/annotations.proto";
  </code></pre>
  
  <p>I am getting an error on the line above saying "file not found".
  When I copy the files inside my project, they are found but when I run the command</p>
  
  <pre><code>protoc -I/usr/local/include -I. \
    -I$GOPATH/src \
    -I$GOPATH/src/github.com/grpc-ecosystem/grpc-gateway/third_party/googleapis \
    --go_out=plugins=grpc:. \
    path/to/your_service.proto
  </code></pre>
  
  <p>it will complain that it cannot find the files.</p>
  
  <p>Could someone please tell me the correct way on how to be able to get this grpc-gateway working properly?</p>
  
  <p>I am currently on windows with GoLand as IDE.</p>