CI: setup Xvbf

.github/workflows/cross_release.yaml

@@ -13,23 +13,28 @@ jobs:
     steps:
       - name: Checkout Repository
         uses: actions/checkout@v4
-
+      
       - name: Set Up Python
         uses: actions/setup-python@v4
         with:
           python-version: '3.10'
 
-      - name: Install Dependencies
-        run: pip install -r requirements.txt
+      - name: Run headless test
+        uses: coactions/setup-xvfb@v1
+        with:
+          run: |
+            export DISPLAY=:99
+            Xvfb :99 -screen 0 1024x768x24 > /dev/null 2>&1 &
+            sleep 3
+            pip install -r requirements.txt
+            pytest --cov=solver --cov=parser --cov=plotter
+        
+      # - name: Install Dependencies
+      #   run: pip install -r requirements.txt
 
-      - name: Set Matplotlib Backend
-        run: echo "MPLBACKEND=TkAgg" >> $GITHUB_ENV
-
-      - name: Debug Matplotlib Backend
-        run: python -c "import matplotlib; print(matplotlib.get_backend())"
 
-      - name: Run Tests
-        run: pytest --cov=solver --cov=parser --cov=plotter
+      # - name: Run Tests
+      #   run: pytest --cov=solver --cov=parser --cov=plotter
 
   build:
     needs: test