* [Write good commit messages.](https://cbea.ms/git-commit/#seven-rules)
* [Sign off your commits](https://git-scm.com/docs/git-commit#Documentation/git-commit.txt---signoff) to indicate that you agree to the terms of [Developer Certificate of Origin](https://developercertificate.org/). We can only accept PRs that have all commits signed off.
* Keep commits discrete. Avoid including multiple unrelated changes in a single commit.

1.  Using tools and libraries installed directly on your system.

    Refer to the
    [CPU-only developer Dockerfile](https://github.com/tensorflow/tensorflow/blob/master/tensorflow/tools/dockerfiles/dockerfiles/devel-cpu.Dockerfile)
    and
    [GPU developer Dockerfile](https://github.com/tensorflow/tensorflow/blob/master/tensorflow/tools/dockerfiles/dockerfiles/devel-gpu.Dockerfile)