message: Made the variable read-only reference.
  Trival fix in the file.
diff: @@ -54,7 +54,7 @@ void ReduceGeneric(bool keep_dims, const std::vector<int>& axes,
  // Reduction mask will be elementwise multiplied against the input
  // indices to figure out the output index for the element.
  std::vector<int> reduction_mask(input_shape.dimensions_count(), 1);
  - for (int axis : axes) {
  + for (const auto& axis : axes) {
  CHECK_GE(axis, 0);
  CHECK_LT(axis, input_shape.dimensions_count());
  reduction_mask[axis] = 0;
  