PyTorch Workflow Cheatsheet

Context

This is a quick cheatsheet of common operations PyTorch developers use.

Developing a new feature

git checkout upstream viable/strict
git branch my-awesome-feature
git checkout my-awesome-feature

Checkout the PyTorch viable/strict branch. All PyTorch tests are guaranteed to be passing on the viable/strict branch (as opposed to the master branch, where they might not pass). viable/strict lags behind PyTorch's master branch and is automatically advanced whenever a new commit to master passes all tests. More details here

Create a new branch that is based on viable/strict and make some changes to PyTorch.

Building and testing PyTorch

When you've made some changes to PyTorch, build and test PyTorch. PyTorch has a lot of build flags; if you turn off some of them your build will go faster. The most important one is USE_CUDA, which defaults to 1. If your machine doesn't have a GPU, you probably want to build without CUDA: USE_CUDA=0

USE_KINETO=0 BUILD_CAFFE2=0 USE_DISTRIBUTED=0 USE_NCCL=0 BUILD_TEST=0 USE_XNNPACK=0 USE_FBGEMM=0 USE_QNNPACK=0 USE_MKLDNN=0 USE_MIOPEN=0 USE_NNPACK=0 BUILD_CAFFE2_OPS=0 USE_TENSORPIPE=0 python setup.py develop

PyTorch has a lot of test files under test/. You'll have to pick one (or a couple) that you want to test.

python test/test_torch.py

More details here

Submitting a change (the traditional way)

git push to the branch on your PyTorch fork. Then, open a pull request.

Submitting a change (using ghstack)

Run ghstack, if you have ghstack installed.

Rebasing your Pull Request (the traditional way)

Your Pull Request is too old and you want to rebase it onto a newer commit. What do you do?

git checkout my-awesome-feature
git pull --rebase upstream viable/strict
git push -f

The idea is to pull Pytorch into your branch while rebasing your (uncommited) commits on top of the newer ones. For example, if PyTorch's viable/strict branch looks like A -> B -> C, and you've made a new commit D at an older stage in time (A -> D), then git pull --rebase viable/strict will change your history to look like A -> B -> C -> D

Rebasing your Pull Request (if it was submitted via ghstack)

Your ghstack-created Pull Request is too old and you want to rebase it onto a newer commit. What do you do?

You have two options:

# Option 1: checkout the pull request using ghstack
ghstack checkout <pull_request_url>
git pull --rebase upstream viable/strict
ghstack

# Option 2: checkout the branch with your changes where you originally ran `ghstack`:
git checkout my-awesome-feature
git pull --rebase upstream viable/strict
ghstack

How to undo (almost) anything with Git

Did you run git pull upstream viable/strict instead of git pull --rebase upstream viable/strict and regret it? See https://github.blog/2015-06-08-how-to-undo-almost-anything-with-git/