protoc
needs to be installed.
```shell
PROTOCVERSION="3.11.2"
PROTOCRELEASE="protoc-$PROTOCVERSION-linux-x8664.zip"
curl -OL "https://github.com/protocolbuffers/protobuf/releases/download/v$PROTOCVERSION/$PROTOCRELEASE" sudo unzip -o $PROTOCRELEASE -d /usr/local bin/protoc sudo unzip -o $PROTOCRELEASE -d /usr/local 'include/*' ```