use cache if available, but do not upload it

[Ben-grmbl]

Is it possible to use an existing cache entry, if a matching one exist, but not upload any at the end, if there is none?

My use case:

• a python project with multiple optional dependency groups
• a matrix workflow that executes tests with multiple combinations of these optional dependencies

so for each matrix test, only certain dependencies are included with uv sync --extra ....

I want to cache only the version with all dependencies.

But depending on which workflow finishes first, after the lock file changes, that workflow's subset of features will be uploaded

I could of course execute uv sync --all-extras after the tests, but that seems wasteful.

Is there a way to disable uploading the new cache for specific cases?

[eifinger]

I see two options to achieve this with the existing functionality:

Option 1 - Populate cache job

Run a job which uses setup-uv and calls uv sync --all-extras. Make all other jobs you mention above dependant on that job so you know the full cache is available.

Option 2 - Upload distinct caches per dependency group "set"

Use cache-suffix to add a unique identifier for each sets of dependencies included in the up-/downloaded cache.

Option 1 should suite your described needs.

[Ben-grmbl]

Thanks for your help!

Option 2 is what I currently use, but it causes a lot of distinct cache entries.

Option 1 I was trying to avoid so far - there are a lot of large dependencies, and even with uv and caching, it takes some time to sync them. I'll see whether I can somehow refactor it so one of the tests always runs first, unless I can come up with a better idea

[eifinger]

As I understand it there is currently no bug or missing feature. Feel free to reopen if you need more feedback.