And then add the `PYTHON_FLAGS` as your cmake flags:
```bash
cmake ..
${PYTHON_FLAGS}\
-DWITH_GPU=OFF \
...
```
You can find more details about cmake flags at [here](http://www.paddlepaddle.org/docs/develop/documentation/fluid/en/build_and_install/build_from_source_en.html#appendix-build-options)