github: Add gcc build

Author: mrannanj

.github/workflows/compilation.yml

@@ -55,6 +55,36 @@ jobs:
           cd build-test
           ctest --verbose --output-on-failure
 
+  # Run unittests on GCC compilation
+  # -----------------------------------------------------------------------------------------------
+  gcc_unittest:
+    name: GCC Linux unittests
+    runs-on: ubuntu-26.04
+
+    steps:
+      - uses: actions/checkout@v6
+
+      - name: Install dependencies
+        uses: Eeems-Org/apt-cache-action@v1.5
+        with:
+          packages: cmake cmake-data ninja-build libcunit1-dev
+            libsdl2-mixer-dev libconfuse-dev libenet-dev libsdl2-dev libxmp-dev libpng-dev
+            libopusfile-dev libepoxy-dev libminiupnpc-dev libnatpmp-dev gcc
+
+      - name: Build tests
+        run: |
+          cmake -DCMAKE_C_COMPILER=gcc \
+                -DUSE_TESTS=On \
+                -DUSE_TOOLS=On \
+                -G "Ninja Multi-Config" \
+                -S . -B build-test
+          cmake --build build-test -j $(getconf _NPROCESSORS_ONLN)
+
+      - name: Run tests
+        run: |
+          cd build-test
+          ctest --verbose --output-on-failure
+
   # Run unittests on a recent version of MSVC
   # -----------------------------------------------------------------------------------------------
   windows_units:
@@ -117,7 +147,7 @@ jobs:
   # Build ubuntu package, release artifact
   # -----------------------------------------------------------------------------------------------
   build_ubuntu:
-    needs: [unittest, windows_units]
+    needs: [unittest, gcc_unittest, windows_units]
     name: Build ubuntu-26.04
     runs-on: ubuntu-26.04
     steps: