How to cache poetry install for GitHub Actions

Question

I tried to use this actions/cache@v2 to cache poetry venv. There are only two libraries pylint and pytest installed. It seems that installation was cached (cache size ~ 26MB). However, they couldn't be retrieved after cache hit.

The cache installed libraries are not found while run

poetry run pip list

Package    Version
---------- -------
pip        20.1.1
setuptools 41.2.0 

https://github.com/northtree/poetry-github-actions/runs/875926237?check_suite_focus=true#step:9:1

The YAML is here.

Could I know how to use actions/cache@v2 to cache poetry installation / virturalenv to avoid reinstalling dependencies.

Answer 1

@northtree's answer is correct, but for anyone browsing, you should know that the referenced action is no longer maintained.

For Poetry installs using versions >= 1.1.0 I'd recommend using this snippet to cache your Poetry dependencies:

...
- name: Install poetry
  uses: snok/[email protected]
  with:
    virtualenvs-create: true
    virtualenvs-in-project: true
- name: Load cached venv
  id: cached-poetry-dependencies
  uses: actions/cache@v2
  with:
    path: .venv
    key: venv-${{ runner.os }}-${{ hashFiles('**/poetry.lock') }}
- name: Install dependencies
  run: poetry install
  if: steps.cached-poetry-dependencies.outputs.cache-hit != 'true'
...

More complete examples are documented here :)