Building target `copy_paddle_pybind` fails

[varunarora]

Here is the error:

In file included from /secret/path/on/my/computer/Paddle/paddle/fluid/platform/profiler.cc:15:
/secret/path/on/my/computer/Paddle/paddle/fluid/platform/profiler.h:128:7: error: private field
      'block_id_' is not used [-Werror,-Wunused-private-field]
  int block_id_;
      ^
/secret/path/on/my/computer/Paddle/paddle/fluid/platform/profiler.h:136:12: error: private field
      'start_ns_' is not used [-Werror,-Wunused-private-field]
  uint64_t start_ns_;
           ^

Reproduce by pulling the newest develop.