[rb] install fluxbox for linux tests

Author: titusfortner

Diff for: .github/workflows/ruby-examples.yml

@@ -41,9 +41,13 @@ jobs:
         if: matrix.os != 'windows'
         run: |
           sudo rm -rf $CHROMEWEBDRIVER $EDGEWEBDRIVER $GECKOWEBDRIVER
-      - name: Start Xvfb
-        if: matrix.os == 'ubuntu'
-        run: Xvfb :99 &
+      - name: Setup Fluxbox and Xvfb
+        if: inputs.os == 'ubuntu'
+        run: |
+          sudo apt-get -y install fluxbox
+          Xvfb :99 &
+          fluxbox -display :99 &
+          echo "DISPLAY=:99" >> "$GITHUB_ENV"
       - name: Set up Ruby
         uses: ruby/setup-ruby@v1
         with:
@@ -89,13 +93,23 @@ jobs:
         with:
           timeout_minutes: 20
           max_attempts: 2
-          command: cd examples/ruby && bundle exec rspec
-          new_command_on_retry: $env:DEBUG=true cd examples/ruby && bundle exec rspec --only-failures
+          command: |
+            cd examples/ruby
+            bundle exec rspec
+          new_command_on_retry: |
+            $env:DEBUG="true"
+            cd examples/ruby
+            bundle exec rspec --only-failures
       - name: Run tests on Linux/Mac
         if: matrix.os != 'windows'
         uses: nick-invision/retry@v3.0.2
         with:
           timeout_minutes: 20
           max_attempts: 2
-          command: cd examples/ruby && bundle exec rspec
-          new_command_on_retry: DEBUG="true" cd examples/ruby && bundle exec rspec --only-failures
+          command: |
+            cd examples/ruby
+            bundle exec rspec
+          new_command_on_retry: |
+            DEBUG="true"
+            cd examples/ruby
+            bundle exec rspec --only-failures