sbt-protoc | SBT plugin for generating code | Plugin library

From the docs:

If you are using sbt-protoc and importing protos like scalapb/scalapb.proto, or common protocol buffers like google/protobuf/wrappers.proto:

Add the following to your build.sbt:

libraryDependencies += "com.thesamet.scalapb" %% "scalapb-runtime" % scalapb.compiler.Version.scalapbVersion % "protobuf"

This tells sbt-protoc to extract protos from this jar (and all its dependencies, which includes Google's common protos), and make them available in the include path that is passed to protoc.

It is important to add that by setting preserve_unknown_fields to false you are turning off a protobuf feature that could prevent data loss when different parts of a distributed system are not running the same version of the schema.

sbt files in the project directory are evaluated before a specific scala version is picked up for cross building. This is why passing ++2.11.12 has no effect on scalaBinaryVersion in the context of project/scalapb.sbt.

Using different versions of compilerplugin in a single build is not officially supported at this point, but there are a few workarounds that you can try:

1. Download scalapbc for the version of ScalaPB you would like to use. Write a shell script that generates sources using ScalaPBC. Check in the generated sources into your code repository. Manually add scalapb-runtime into your libraryDependencies in build.sbt:

In your implementation, you do not have optional fields. If you want to have an optional field you need to write code like this: