[step] Propagate canceled statuses to parent steps

Previously, parent steps of a step that got canceled would always have
their statuses marked as infra failures, which is confusing because it
makes it look like there are multiple different failure modes going on,
when in fact all the step failures are due to the cancelation.

This also fixes some cases where a parent step was incorrectly marked as
an infra failure because the nested code raised an exception that was a
subclass of `StepFailure` - the old code used exact equality of
exception types, whereas the new code correctly handles subclasses. This
is why this CL causes nontrivial rolls into several downstream recipe

Before: https://screenshot.googleplex.com/9CGoNYiRjYQRHaV
After: https://screenshot.googleplex.com/8YWXwix3BYvQyWR

Recipe-Nontrivial-Roll: chromiumos
Recipe-Nontrivial-Roll: fuchsia
Recipe-Nontrivial-Roll: pigweed
Change-Id: I32737a5fc4d3d82a78dc31c878baa12db86ac205
Reviewed-on: https://chromium-review.googlesource.com/c/infra/luci/recipes-py/+/5540028
Reviewed-by: Chan Li <chanli@chromium.org>
Commit-Queue: Oliver Newman <olivernewman@google.com>
Reviewed-by: Robbie Iannucci <iannucci@chromium.org>
4 files changed
tree: 0c5197ae54b42a83c79745845708afcb3e2a6ad5
  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.