The Gradle daemon is not useful for ephemeral builds, and the process
can hold file locks which interfere with cache entry generation.
In the case where multiple Gradle invocations occur in the same job,
we could provide a way for users to override this behaviour, taking care
of stopping any daemon process at the end of the job.
- Do not restore cache when GUH exists
- Include RUNNER_OS in the cache key
- Do not save cache on exact hit
- Only save cache in the final post action
- Log before saving cache
- Provide a more useful error message when no Gradle wrapper can be located,
and 'gradle-version' or 'gradle-executable' is not used.
- Add test for case where wrapper is missing.
This isn't really a "test" per-se, but this failing build invocation makes it
easy to verify the GitHub action behaviour when the build is misconfigured.
