feat(audience): enable Linux compilation, run Linux PlayMode on GameCI (SDK-255)

- Adds LinuxStandalone64 to includePlatforms in the Audience Runtime and
  Audience.Unity asmdefs so the SDK compiles on Linux. The Tests asmdef
  already included Linux; the runtime asmdefs were the gap that prevented
  the sample app from finding any audience SDK types on a Linux build.
- Replaces the two self-hosted Linux matrix cells in test-audience-sample-app.yml
  with a new playmode-linux job that uses game-ci/unity-test-runner@v4 on
  ubuntu-latest-8-cores. Win/macOS cells stay self-hosted as before.
- Removes the Linux-only steps the self-hosted path needed (build-essential
  preflight, Unity Hub headless install, license activation, run, log
  capture, compile-error annotations). GameCI's Docker image bundles the
  editor, the linux-il2cpp module, and the runtime libs, and the action
  handles license activation against the existing UNITY_EMAIL/UNITY_PASSWORD/
  UNITY_SERIAL secrets.

Frees up the self-hosted Linux runner and removes the runner-host setup
burden (libssl1.1, build-essential, manual Unity Hub install, etc.).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: ImmutableJeffrey

.github/workflows/test-audience-sample-app.yml

@@ -46,16 +46,6 @@ jobs:
             unity: 2021.3.45f2
             changeset: 88f88f591b2e
             runner: [self-hosted, macOS, ARM64]
-          - target: StandaloneLinux64
-            backend: IL2CPP
-            unity: 2021.3.45f2
-            changeset: 88f88f591b2e
-            runner: [self-hosted, X64, Linux]
-          - target: StandaloneLinux64
-            backend: Mono2x
-            unity: 2021.3.45f2
-            changeset: 88f88f591b2e
-            runner: [self-hosted, X64, Linux]
           - target: StandaloneWindows64
             backend: IL2CPP
             unity: 6000.4.0f1
@@ -194,25 +184,6 @@ jobs:
           Write-Host "Verified VC.Tools at: $($state.VcTools)"
           Write-Host "Verified Win10 SDK at: $($state.Win10Sdk)"
 
-      - name: Verify IL2CPP toolchain (Linux)
-        if: runner.os == 'Linux' && matrix.backend == 'IL2CPP'
-        shell: bash
-        run: |
-          # IL2CPP's C++ to native step links against gcc/g++ + glibc-dev (the
-          # build-essential package on Ubuntu). Without these, Unity fails late
-          # inside the IL2CPP build with a cryptic linker error. Fail fast here
-          # with a clear remediation message instead.
-          MISSING=""
-          for cmd in gcc g++; do
-            command -v "$cmd" >/dev/null 2>&1 || MISSING="${MISSING:+$MISSING+}$cmd"
-          done
-          if [ -n "$MISSING" ]; then
-            echo "::error::IL2CPP toolchain incomplete on runner: $MISSING. Run on the runner host: sudo apt install -y build-essential"
-            exit 1
-          fi
-          echo "gcc: $(gcc --version | head -1)"
-          echo "g++: $(g++ --version | head -1)"
-
       - name: Resolve Unity ${{ matrix.unity }} (macOS)
         if: runner.os == 'macOS'
         shell: bash
@@ -309,79 +280,6 @@ jobs:
           if ('${{ matrix.backend }}' -eq 'IL2CPP') { Write-Host "Found IL2CPP: $il2cpp" }
           "UNITY_PATH=$editor" | Out-File -FilePath $env:GITHUB_ENV -Append -Encoding utf8
 
-      - name: Resolve Unity ${{ matrix.unity }} (Linux)
-        if: runner.os == 'Linux'
-        shell: bash
-        env:
-          UNITY_VER: ${{ matrix.unity }}
-          UNITY_CS: ${{ matrix.changeset }}
-        run: |
-          set -uo pipefail
-          HUB="unityhub"
-
-          echo "::group::install editor"
-          "$HUB" --headless install \
-            --version "$UNITY_VER" --changeset "$UNITY_CS" --architecture x86_64 \
-            || echo "(install non-zero, OK if 'Editor already installed in this location')"
-          echo "::endgroup::"
-
-          if [ "${{ matrix.backend }}" = "IL2CPP" ]; then
-            echo "::group::install linux-il2cpp module"
-            "$HUB" --headless install-modules \
-              --version "$UNITY_VER" --changeset "$UNITY_CS" --architecture x86_64 \
-              --module linux-il2cpp \
-              || echo "(install-modules non-zero, OK if 'No modules found to install')"
-            echo "::endgroup::"
-          fi
-
-          EDITOR_PATH="$HOME/Unity/Hub/Editor/$UNITY_VER/Editor/Unity"
-
-          IL2CPP_DIR=""
-          if [ "${{ matrix.backend }}" = "IL2CPP" ] && [ -x "$EDITOR_PATH" ]; then
-            IL2CPP_DIR="$HOME/Unity/Hub/Editor/$UNITY_VER/Editor/Data/PlaybackEngines/LinuxStandaloneSupport/Variations/linux64_player_nondevelopment_il2cpp"
-            [ -d "$IL2CPP_DIR" ] || IL2CPP_DIR=""
-          fi
-
-          MISSING=""
-          [ -x "$EDITOR_PATH" ] || MISSING="editor"
-          [ "${{ matrix.backend }}" = "IL2CPP" ] && [ -z "$IL2CPP_DIR" ] && MISSING="${MISSING:+$MISSING+}linux-il2cpp"
-          if [ -n "$MISSING" ]; then
-            echo "::error::Unity $UNITY_VER missing: $MISSING"
-            ls -la "$HOME/Unity/Hub/Editor/" 2>&1 || true
-            "$HUB" --headless editors --installed 2>&1 || true
-            exit 1
-          fi
-
-          echo "Found Unity:  $EDITOR_PATH"
-          [ -n "$IL2CPP_DIR" ] && echo "Found IL2CPP: $IL2CPP_DIR"
-          echo "UNITY_PATH=$EDITOR_PATH" >> "$GITHUB_ENV"
-
-      - name: Activate Unity license (Linux)
-        if: runner.os == 'Linux'
-        shell: bash
-        env:
-          UNITY_EMAIL: ${{ secrets.UNITY_EMAIL }}
-          UNITY_PASSWORD: ${{ secrets.UNITY_PASSWORD }}
-          UNITY_SERIAL: ${{ secrets.UNITY_SERIAL }}
-        run: |
-          set -uo pipefail
-          LOG="$(mktemp)"
-          echo "::group::Activate Unity"
-          "$UNITY_PATH" -batchmode -nographics -quit \
-            -username "$UNITY_EMAIL" \
-            -password "$UNITY_PASSWORD" \
-            -serial   "$UNITY_SERIAL" \
-            -logFile - 2>&1 | tee "$LOG" || true
-          echo "::endgroup::"
-
-          if grep -qE "(Successfully activated the entitlement license|Successfully processed license management request)" "$LOG"; then
-            echo "Unity license is active"
-            exit 0
-          fi
-
-          echo "::error::Unity activation failed. Check UNITY_EMAIL/UNITY_PASSWORD/UNITY_SERIAL secrets and seat-pool availability."
-          exit 1
-
       - name: Run PlayMode tests (macOS)
         if: runner.os == 'macOS'
         shell: bash
@@ -431,26 +329,6 @@ jobs:
           Write-Host "Unity exited with code $exit"
           if ($exit -ne 0) { exit $exit }
 
-      - name: Run PlayMode tests (Linux)
-        if: runner.os == 'Linux'
-        shell: bash
-        env:
-          AUDIENCE_TEST_PUBLISHABLE_KEY: ${{ secrets.AUDIENCE_TEST_PUBLISHABLE_KEY }}
-          AUDIENCE_SCRIPTING_BACKEND: ${{ matrix.backend }}
-        run: |
-          set -euo pipefail
-          mkdir -p artifacts
-          # Mirrors the macOS variant: tee Unity's stdout to artifacts/unity.log
-          # so the annotation step has a file to scan while progress streams to
-          # the job log. pipefail propagates Unity's exit code through tee.
-          "$UNITY_PATH" \
-            -batchmode -nographics \
-            -projectPath examples/audience \
-            -runTests \
-            -testPlatform ${{ matrix.target }} \
-            -testResults "$(pwd)/artifacts/test-results.xml" \
-            -logFile - 2>&1 | tee "$(pwd)/artifacts/unity.log"
-
       - name: Mark workspace safe for git (Windows)
         if: always() && runner.os == 'Windows'
         shell: pwsh
@@ -491,21 +369,6 @@ jobs:
               }
           }
 
-      - name: Capture player log (Linux)
-        if: always() && runner.os == 'Linux'
-        shell: bash
-        run: |
-          # See macOS counterpart for rationale. Linux player log location:
-          # ~/.config/unity3d/<CompanyName>/<ProductName>/Player.log (Unity's
-          # standard persistent data path on Linux, matching $XDG_CONFIG_HOME).
-          mkdir -p artifacts
-          src="$HOME/.config/unity3d"
-          if [ -d "$src" ]; then
-            find "$src" -name "Player.log" 2>/dev/null | while IFS= read -r f; do
-              cp "$f" "artifacts/Player-$(basename "$(dirname "$f")").log" 2>/dev/null || true
-            done
-          fi
-
       - name: Surface Unity compile errors as annotations (macOS)
         if: always() && runner.os == 'macOS'
         shell: bash
@@ -551,23 +414,6 @@ jobs:
               Write-Host "::error::$sanitized"
             }
 
-      - name: Surface Unity compile errors as annotations (Linux)
-        if: always() && runner.os == 'Linux'
-        shell: bash
-        run: |
-          set -uo pipefail
-          # See macOS counterpart for rationale.
-          LOG_FILE="artifacts/unity.log"
-          if [ ! -f "$LOG_FILE" ]; then
-            echo "::notice::No Unity log file at $LOG_FILE."
-            exit 0
-          fi
-          grep -E '(error CS[0-9]+:|Compilation failed:)' "$LOG_FILE" | sort -u | while IFS= read -r line; do
-            trimmed="${line#"${line%%[![:space:]]*}"}"
-            sanitized="${trimmed//::/%3A%3A}"
-            echo "::error::$sanitized"
-          done || true
-
       - name: Publish test report
         uses: dorny/test-reporter@v3
         if: always()
@@ -587,6 +433,66 @@ jobs:
             artifacts/Player-*.log
             examples/audience/Logs/**
 
+  # Linux PlayMode runs on GitHub-hosted Ubuntu via GameCI Docker, not on the
+  # self-hosted matrix above, to keep self-hosted machines free for Win/macOS.
+  playmode-linux:
+    if: github.event.pull_request.head.repo.fork == false || github.event_name == 'workflow_dispatch'
+    name: ${{ matrix.target }} / ${{ matrix.backend }} / Unity ${{ matrix.unity }}
+    runs-on: ubuntu-latest-8-cores
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - target: StandaloneLinux64
+            backend: IL2CPP
+            unity: 2021.3.45f2
+          - target: StandaloneLinux64
+            backend: Mono2x
+            unity: 2021.3.45f2
+
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          lfs: true
+
+      - uses: actions/cache@v4
+        with:
+          path: examples/audience/Library
+          key: Library-${{ matrix.backend }}-${{ matrix.target }}-${{ matrix.unity }}-${{ hashFiles('examples/audience/Assets/**', 'examples/audience/Packages/**', 'examples/audience/ProjectSettings/**', 'src/Packages/Audience/**') }}
+          restore-keys: |
+            Library-${{ matrix.backend }}-${{ matrix.target }}-${{ matrix.unity }}-
+            Library-${{ matrix.backend }}-${{ matrix.target }}-
+
+      - uses: game-ci/unity-test-runner@v4
+        id: playmode
+        env:
+          UNITY_EMAIL: ${{ secrets.UNITY_EMAIL }}
+          UNITY_PASSWORD: ${{ secrets.UNITY_PASSWORD }}
+          UNITY_SERIAL: ${{ secrets.UNITY_SERIAL }}
+          AUDIENCE_TEST_PUBLISHABLE_KEY: ${{ secrets.AUDIENCE_TEST_PUBLISHABLE_KEY }}
+          AUDIENCE_SCRIPTING_BACKEND: ${{ matrix.backend }}
+        with:
+          unityVersion: ${{ matrix.unity }}
+          targetPlatform: ${{ matrix.target }}
+          projectPath: examples/audience
+          testMode: playmode
+          githubToken: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Publish test report
+        uses: dorny/test-reporter@v3
+        if: always()
+        with:
+          name: PlayMode (${{ matrix.backend }} / ${{ matrix.target }})
+          path: ${{ steps.playmode.outputs.artifactsPath }}/playmode-results.xml
+          reporter: dotnet-nunit
+          fail-on-error: true
+
+      - uses: actions/upload-artifact@v4
+        if: always()
+        with:
+          name: playmode-${{ matrix.backend }}-${{ matrix.target }}-${{ matrix.unity }}
+          path: ${{ steps.playmode.outputs.artifactsPath }}
+
   # Mobile IL2CPP build validation — runs on GitHub-hosted Ubuntu via GameCI Docker
   # containers so self-hosted macOS/Windows machines are not occupied.
   # Scope: IL2CPP compile pipeline only. Runtime tests require a real device and

src/Packages/Audience/Runtime/Unity/com.immutable.audience.unity.asmdef

@@ -2,7 +2,7 @@
     "name": "Immutable.Audience.Unity",
     "rootNamespace": "Immutable.Audience.Unity",
     "references": ["Immutable.Audience.Runtime"],
-    "includePlatforms": ["Android", "Editor", "iOS", "macOSStandalone", "WindowsStandalone64"],
+    "includePlatforms": ["Android", "Editor", "iOS", "LinuxStandalone64", "macOSStandalone", "WindowsStandalone64"],
     "excludePlatforms": [],
     "allowUnsafeCode": false,
     "overrideReferences": false,

src/Packages/Audience/Runtime/com.immutable.audience.asmdef

@@ -2,7 +2,7 @@
     "name": "Immutable.Audience.Runtime",
     "rootNamespace": "Immutable.Audience",
     "references": [],
-    "includePlatforms": ["Android", "Editor", "iOS", "macOSStandalone", "WindowsStandalone64"],
+    "includePlatforms": ["Android", "Editor", "iOS", "LinuxStandalone64", "macOSStandalone", "WindowsStandalone64"],
     "excludePlatforms": [],
     "allowUnsafeCode": false,
     "overrideReferences": false,