astral-sh/setup-uv installs uv, puts it on PATH and, on GitHub-hosted runners, saves the uv cache under a key built from the platform, the Python version and a hash of your dependency files. Since v8 it publishes no major tags, so astral-sh/setup-uv@v10 does not resolve: pin a full version or a commit SHA.

No restore keys: a changed lockfile is a cold cache. Read from src/utils/inputs.ts, src/cache/restore-cache.ts and src/save-cache.ts at v10.3.3 on 2026-11-12.

Most setup-uv questions are one of three: why @v8 , @v9 or @v10 fails to resolve, why the cache never restores on a branch or on a self-hosted runner, and whether you still need actions/setup-python . The answers are in the release notes and in a few lines of src/utils/inputs.ts and src/cache/restore-cache.ts .

The first stops a workflow before any step runs. setup-uv has published only full version tags since v8, so @v10 , the form most other actions use, is not a ref GitHub can resolve.…