diff -u -r ../cache/checkout-1.20.1/CMakeLists.txt ./CMakeLists.txt
--- ../cache/checkout-1.20.1/CMakeLists.txt	2019-05-05 19:34:14.719680525 +0000
+++ ./CMakeLists.txt	2019-05-05 19:44:36.428274714 +0000
@@ -206,7 +206,7 @@
       COMMAND ${_gRPC_PROTOBUF_PROTOC_EXECUTABLE}
       ARGS --grpc_out=generate_mock_code=true:${_gRPC_PROTO_GENS_DIR}
            --cpp_out=${_gRPC_PROTO_GENS_DIR}
-           --plugin=protoc-gen-grpc=${_gRPC_CPP_PLUGIN}
+	   --plugin=protoc-gen-grpc=@PATH_TO_PLUGIN@
            ${_protobuf_include_path}
            ${REL_FIL}
       DEPENDS ${ABS_FIL} ${_gRPC_PROTOBUF_PROTOC} grpc_cpp_plugin