[engine] Don't warn about empty recipe module directories

When a directory gets deleted from a repository, it doesn't
automatically get cleaned up in people's local clones of the repository.
So when a recipe module gets deleted upstream, people would get annoying
"missing __init__.py" errors from recipes.py commands locally.

I think this error is useful, but only if someone is trying to create a
new recipe module and they forget to add an __init__.py file. In this
case they probably would have added other files to the directory, if we
emit the log only when the directory is non-empty it should continue to
provide value while silencing the logs when they're not useful.

Change-Id: I2ae636a1f740fc5e6bc5e29ec7e1819d9e1c402d
Reviewed-on: https://chromium-review.googlesource.com/c/infra/luci/recipes-py/+/5443305
Reviewed-by: Chan Li <chanli@chromium.org>
Auto-Submit: Oliver Newman <olivernewman@google.com>
Commit-Queue: Oliver Newman <olivernewman@google.com>
4 files changed
tree: 3363b10afe9e5714f5ed1a20eaf3db664609b3cd
  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.