GitHub Actions pip Cache Not Working for Python Projects
Issue
In GitHub Actions workflows for Python projects, pip install times are slow and it appears that the pip cache is not being used between workflow runs. Even when using the actions/cache step, dependencies are reinstalled from scratch. How can pip caching be enabled and made effective in GitHub Actions?
Solution
To enable pip cache in GitHub Actions, you need to cache the pip cache directory. For most systems, this is ~/.cache/pip. Here is an example of how to do this:
- name: Cache pip
uses: actions/cache@v4
with:
path: ~/.cache/pip
key: $-pip-$
restore-keys: |
$-pip-
- name: Install dependencies
run: pip install -r requirements.txt
Make sure the cache key includes a hash of your requirements file. This will ensure the cache is updated when dependencies change. If you use pip install --no-cache-dir, remove that flag to allow caching.