Fix macos github actions

.github/workflows/R-CMD-check-macOS.yml

@@ -22,6 +22,10 @@ jobs:
         config:
           - {os: macOS-latest,   r: '4.1.2'}
           - {os: macOS-latest,   r: 'release'}
+          - {os: macOS-13,   r: '4.1.2'}
+          - {os: macOS-13,   r: 'release'}
+          - {os: macOS-12,   r: '4.1.2'}
+          - {os: macOS-12,   r: 'release'}
 
     env:
       R_REMOTES_NO_ERRORS_FROM_WARNINGS: true
@@ -37,6 +41,30 @@ jobs:
 
       - uses: r-lib/actions/setup-pandoc@v2
 
+      - name: Check runner.os
+        run: echo "Operating System ${{ runner.os }}"
+
+      - name: Check matrix.os
+        run: echo "Operating System ${{ matrix.config.os }}"
+
+      - name: Symlink gfortran (macOS 12 or 13)
+        if: ${{ matrix.config.os }} == 'macOS-12' || ${{ matrix.config.os }} == 'macOS-13'
+        run: |
+          # make sure gfortran is available
+          sudo ln -s /usr/local/bin/gfortran-12 /usr/local/bin/gfortran
+          sudo mkdir -p /usr/local/gfortran
+          sudo ln -s /usr/local/Cellar/gcc@12/*/lib/gcc/12 /usr/local/gfortran/lib
+          gfortran --version
+
+      - name: Symlink gfortran (macOS 14)
+        if: ${{ matrix.config.os }} == 'macOS-14'
+        run: |
+          # make sure gfortran is available
+          sudo ln -s /usr/local/bin/gfortran-13 /usr/local/bin/gfortran
+          sudo mkdir -p /usr/local/gfortran
+          sudo ln -s /usr/local/Cellar/gcc@13/*/lib/gcc/13 /usr/local/gfortran/lib
+          gfortran --version
+
       - name: Install dependencies
         run: Rscript -e "install.packages(c('devtools', dependencies=TRUE))" -e "install.packages(c('rcmdcheck', 'devtools', 'Rcpp', 'RcppEigen', 'BH', 'testthat', 'downloader', 'xfun'))";