CI: Add GFortran 15 testing on macOS

Linux package not yet available, but lay the groundwork to deploy it later

Author: bonachea

.github/workflows/build.yml

@@ -13,18 +13,20 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [macos-13, macos-14, macos-15, ubuntu-22.04, ubuntu-24.04]
+        os: [macos-13, macos-14, macos-15, ubuntu-24.04]
         compiler: [ gfortran ]
-        version: [ 12, 13, 14 ]
+        version: [ 12, 13, 14, 15 ]
         extra_flags: [ -g ]
 
         exclude:
-          - os: ubuntu-22.04
-            version: 13 # no package available
-          - os: ubuntu-22.04
-            version: 14 # no package available
+          - os: ubuntu-24.04
+            version: 15 # no package available (yet?)
 
         include:
+          - os: ubuntu-22.04
+            compiler: gfortran
+            version: 12 # no package available for gfortran 13+
+
           # --- LLVM flang coverage ---
 
           - os: macos-13
@@ -104,15 +106,13 @@ jobs:
     - name: Checkout code
       uses: actions/checkout@v4
 
-    - name: Install Dependencies Ubuntu
-      if: ${{ contains(matrix.os, 'ubuntu') && matrix.compiler == 'gfortran' && 0 }}
+    - name: Install Ubuntu Native Dependencies
+      if: ${{ contains(matrix.os, 'ubuntu') && matrix.container == '' && matrix.compiler == 'gfortran' }}
       run: |
-        sudo apt-get update
-        sudo apt list -a 'gfortran-*'
-        sudo apt install -y gfortran-${COMPILER_VERSION} build-essential
-        sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-${COMPILER_VERSION} 100 \
-        --slave /usr/bin/gfortran gfortran /usr/bin/gfortran-${COMPILER_VERSION}
-
+        set -x
+        sudo apt update
+        # sudo apt list -a 'gfortran-*'
+        sudo apt install -y build-essential gfortran-${COMPILER_VERSION}
 
     - name: Install Ubuntu Container Dependencies
       if: ${{ contains(matrix.os, 'ubuntu') && matrix.container != '' && !contains(matrix.container, 'phhargrove') }}