Problem

The unity-tests.yml workflow currently runs only on Unity 2021.3.45f2. Compile errors that are version-specific (e.g. anything that diverges between 2021.3 / 2022.3 / 6000.x APIs) slip through CI and only surface when end users update the package.

Two recent incidents illustrate this:

• Unity 2022.3 compile errors on beta 9.6.9-beta.5 / commit 37ef016 #1100 — CaptureFromCameraToAssetsFolder rename gap. Caught at the merge boundary by post-merge tests on 2021.3 because it failed on every Unity, but Unity Tests was running in parallel with PyPI publish so the broken beta still shipped (now fixed by gating in fix: unblock beta compile and gate releases on test success #1103).
• Unity 2022.3.62f2 Error with latest beta update 9.6.9-beta6 #1105 — UnityFindObjectsCompat 2022.3 compile error. Not catchable by the current CI at all because the bug only manifests on Unity 2022.3.x; CI's lone runner is on 2021.3 where the legacy code path is taken. Patch is in fix: close 2022.3 compile gap in UnityFindObjectsCompat.FindAll #1106 but next equivalent regression will repeat unless we widen the matrix.

Proposal: tiered matrix

Run a fast PR matrix and a thorough push-to-beta matrix:

Per-PR cost stays the same as today. Per-merge-to-beta cost goes up ~3× in runner minutes, but that fires far less frequently than PRs and the existing release-gating in #1103 already blocks PyPI/version-bump on test failure — so widening the matrix at the beta gate is exactly where it has the most leverage.

Implementation sketch

In .github/workflows/unity-tests.yml, switch the matrix to use include: and condition on github.event_name/github.ref:

strategy:
  fail-fast: false
  matrix:
    include:
      - { unityVersion: "2021.3.45f2", projectPath: "TestProjects/UnityMCPTests", testMode: "editmode" }
      # Beta gate adds the wider matrix:
      - { unityVersion: "2022.3.x",    projectPath: "TestProjects/UnityMCPTests", testMode: "editmode" }
      - { unityVersion: "6000.0.x",    projectPath: "TestProjects/UnityMCPTests", testMode: "editmode" }
    exclude:
      - unityVersion: "2022.3.x"
        # only run on push to beta or workflow_call from a release pipeline
      - unityVersion: "6000.0.x"
        # ditto

(The exact gating expression depends on which form actions/runner accepts in exclude:; a conditional skip inside the steps via if: ${{ matrix.unityVersion == '2021.3.45f2' || github.ref == 'refs/heads/beta' }} is more reliable.)

License/cost notes

game-ci/unity-test-runner reuses a single UNITY_LICENSE across parallel matrix entries within one workflow run. Per-job cost is just runner minutes (~3 min × N versions, parallelized), not extra license seats.

Acceptance criteria

• PRs touching MCPForUnity/Editor/** or TestProjects/UnityMCPTests/** still run a quick single-version test in CI.
• Pushes to beta (and the existing workflow_call from beta-release.yml/release.yml) run the wider matrix.
• Matrix failures on any Unity version block the existing update_unity_beta_version and publish_pypi_prerelease jobs.
• Versions are pinned to specific patch releases for reproducibility (no 2022.3.x floating tags in CI).