[recipes.py] Directly set PYTHONPATH to the engine path.

Step 1/2 to remove a bit of sys.path hackery.

Previously main.py would reconfigure sys.path during the execution of
the recipe code in order to make `from recipe_engine import ...` work.
This changes it so that all known executions of main.py (namely
recipes.py and the two bundled launcher scripts) just set PYTHONPATH
correctly prior to invoking main.py.

The next CL will remove the hacky bits from recipe_engine/main.py

R=bryner, fancl, mohrr, yiwzhang

Bug: 1462728
Change-Id: Ibfb8328d9a5b5fa27d617eb66346c4e563f5fab1
Reviewed-on: https://chromium-review.googlesource.com/c/infra/luci/recipes-py/+/5445933
Reviewed-by: Chenlin Fan <fancl@chromium.org>
Reviewed-by: Rob Mohr <mohrr@google.com>
Commit-Queue: Robbie Iannucci <iannucci@chromium.org>
Reviewed-by: Brian Ryner <bryner@google.com>
Reviewed-by: Yiwei Zhang <yiwzhang@google.com>
2 files changed
tree: e6cb2ba01b1e7050d80b2df54fc97d0eca7b8abe
  1. doc/
  2. infra/
  3. misc/
  4. recipe_engine/
  5. recipe_modules/
  6. recipe_proto/
  7. recipes/
  8. unittests/
  9. .editorconfig
  10. .gitattributes
  11. .gitignore
  12. .pycharm.vpython3
  13. .style.yapf
  14. .vpython3
  15. .vscode.vpython3
  17. codereview.settings
  20. OWNERS
  21. PRESUBMIT.py
  22. pyproject.toml
  23. README.md
  24. README.recipes.md
  25. recipe.warnings
  26. recipes.py


Recipes are a domain-specific language (embedded in Python) for specifying sequences of subprocess calls in a cross-platform and testable way.

They allow writing build flows which integrate with the rest of LUCI.

Documentation for the recipe engine (including this file!). Take a look at the user guide for some hints on how to get started. See the implementation details doc for more detailed implementation information about the recipe engine.


  • Sign the Google CLA.
  • Make sure your user.email and user.name are configured in git config.

Run the following to setup the code review tool and create your first review:

# Get `depot_tools` in $PATH if you don't have it
git clone https://chromium.googlesource.com/chromium/tools/depot_tools.git $HOME/src/depot_tools
export PATH="$PATH:$HOME/src/depot_tools"

# Check out the recipe engine repo
git clone https://chromium.googlesource.com/infra/luci/recipes-py $HOME/src/recipes-py

# make your change
cd $HOME/src/recipes-py
git new-branch cool_feature
# hack hack
git commit -a -m "This is awesome"

# This will ask for your Google Account credentials.
git cl upload -s -r joe@example.com
# Wait for approval over email.
# Click "Submit to CQ" button or ask reviewer to do it for you.
# Wait for the change to be tested and landed automatically.

Use git cl help and git cl help <cmd> for more details.