BerkeleyLab · rouson · Nov 22, 2025 · Nov 16, 2025 · Nov 18, 2025 · Nov 18, 2025
diff --git a/.github/workflows/CI.yml b/.github/workflows/CI.yml
@@ -4,44 +4,126 @@ on: [push, pull_request]
 
 jobs:
   Build:
-    runs-on: [ubuntu-latest]
+    name: ${{ matrix.compiler }}-${{ matrix.version }} (${{ matrix.os }})
+    runs-on: ${{ matrix.os }}
+    defaults:
+      run:
+        shell: bash
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ macos-14, macos-15, macos-15-intel, macos-26, ubuntu-24.04 ]
+        compiler: [ gfortran ]
+        version: [ 14 ]
+        extra_flags: [ -g ]
+        oc_version: [ 2.10.3 ]
+
+        include:
+          - os: ubuntu-24.04
+            compiler: gfortran
+            version: 13
+            extra_flags: -g -ffree-line-length-0
+            oc_version: 2.10.3
 
     env:
-      FC: gfortran
-      GCC_V: 14
+      COMPILER_VERSION: ${{ matrix.version }}
+      OC_VERSION: ${{ matrix.oc_version }}
+      FC: ${{ matrix.compiler }}
+      FFLAGS: ${{ matrix.extra_flags }}
+      FPM_FLAGS:  --profile release --verbose
 
     steps:
     - name: Checkout code
       uses: actions/checkout@v4
 
     - name: Install fpm
-      uses: fortran-lang/setup-fpm@v7
+      uses: fortran-lang/setup-fpm@main
       with:
         github-token: ${{ secrets.GITHUB_TOKEN }}
+        fpm-version: latest
 
     - name: Get Time
       id: time
-      uses: nanzm/get-time-action@v1.1
+      uses: nanzm/get-time-action@master
       with:
         format: 'YYYY-MM'
 
-    - name: Setup cache for opencoarrays
+    - name: Install macOS Dependencies
+      if: ${{ contains(matrix.os, 'macos') && matrix.compiler == 'gfortran' && matrix.version == 14 }}
+      run: |
+        set -x
+        brew update
+        # fpm binary distribution for macOS requires gfortran shared libraries from gcc@12
+        brew install -v gcc@12
+        brew install -v opencoarrays gcc@14 open-mpi
+        #brew --prefix
+        #ls -alR $(brew --prefix)/bin
+        echo "FC=gfortran-${COMPILER_VERSION}" >> "$GITHUB_ENV"
+
+    - name: Install Ubuntu Native Dependencies
+      if: ${{ contains(matrix.os, 'ubuntu') && matrix.container == '' && matrix.compiler == 'gfortran' }}
+      run: |
+        set -x
+        sudo apt update
+        sudo apt install -y build-essential pkg-config make
+        sudo apt install -y gfortran-${COMPILER_VERSION} g++-${COMPILER_VERSION}
+
+    - name: OpenCoarrays/MPICH Cache
+      if: ${{ contains(matrix.os, 'ubuntu') && matrix.container == '' }}
       id: cache-opencoarrays
-      uses: actions/cache@v3
+      uses: actions/cache@v4
       with:
-        path: "OpenCoarrays-2.10.2/"
-        key: ${{ steps.time.outputs.time }}
+        path: OpenCoarrays-${{ matrix.oc_version }}
+        key: OpenCoarrays-${{ matrix.oc_version }}-${{ matrix.compiler }}-${{ matrix.version }}-${{ matrix.os }}-${{ steps.time.outputs.time }}
 
-    - name: Install GFortran, OpenCoarrays
+    - name: OpenCoarrays/MPICH Build
+      if: ${{ steps.cache-opencoarrays.outputs.cache-hit != 'true' && contains(matrix.os, 'ubuntu') && matrix.container == '' }}
       run: |
-        sudo apt update
-        sudo apt install -y build-essential gfortran-${GCC_V} g++-${GCC_V} pkg-config make
-        sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-${GCC_V} 100 \
-          --slave /usr/bin/gfortran gfortran /usr/bin/gfortran-${GCC_V} \
-          --slave /usr/bin/g++ g++ /usr/bin/g++-${GCC_V}
-        if [ ! -d OpenCoarrays-2.10.2 ] ; then wget -P . https://github.com/sourceryinstitute/OpenCoarrays/releases/download/2.10.2/OpenCoarrays-2.10.2.tar.gz && tar -xf OpenCoarrays-2.10.2.tar.gz && cd OpenCoarrays-2.10.2 && TERM=xterm ./install.sh -y; fi
+          set -x
+          rm -Rf OpenCoarrays-${OC_VERSION}
+          #OC_URL=https://github.com/sourceryinstitute/OpenCoarrays/releases/download/${OC_VERSION}/OpenCoarrays-${OC_VERSION}.tar.gz
+          OC_URL=https://github.com/sourceryinstitute/OpenCoarrays/archive/refs/tags/${OC_VERSION}.tar.gz
+          wget -P . ${OC_URL}
+          tar -xf ${OC_VERSION}.tar.gz
+          cd OpenCoarrays-${OC_VERSION}
+          TERM=xterm ./install.sh --yes-to-all \
+            --with-fortran gfortran-${COMPILER_VERSION} \
+            --with-cxx g++-${COMPILER_VERSION} \
+            --with-c gcc-${COMPILER_VERSION}
+
+    - name: Setup Ubuntu Compilers
+      if: ${{ contains(matrix.os, 'ubuntu') && matrix.container == '' && matrix.compiler == 'gfortran' }}
+      run: |
+        set -x
+        PREFIX="$PWD/OpenCoarrays-${OC_VERSION}/prerequisites/installations"
+        OC_PATH="$PREFIX/opencoarrays/${OC_VERSION}"
+        MPI_PATH=$(ls -d $PREFIX/mpich/*)
+        #ls -alR ${PREFIX}
+        cat ${OC_PATH}/setup.sh
+        echo "PATH=${OC_PATH}/bin:${MPI_PATH}/bin:$PATH" >> "$GITHUB_ENV"
+        echo "FC=gfortran-${COMPILER_VERSION}" >> "$GITHUB_ENV"
+        echo "FPM_FFLAGS=${FFLAGS}" >> "$GITHUB_ENV"
+        echo "FPM_CFLAGS=${CFLAGS}" >> "$GITHUB_ENV"
+        echo "FPM_CXXFLAGS=${CXXFLAGS}" >> "$GITHUB_ENV"
+        echo "FPM_LDFLAGS=${LDFLAGS}" >> "$GITHUB_ENV"
+
+    - name: Version info
+      run: |
+        echo == TOOL VERSIONS ==
+        echo Platform version info:
+        uname -a
+        if test -r /etc/os-release ; then grep -e NAME -e VERSION /etc/os-release  ; fi
+        if test -x /usr/bin/sw_vers ; then /usr/bin/sw_vers ; fi
+        echo
+        echo PATH="$PATH"
+        for tool in ${FC} caf mpicc mpif90 fpm ; do
+          ( echo ; set -x ; w=$(which $tool) ; \
+            if test -n "$w" ; then \
+               ls -al $w ; ls -alhL $w ; $tool --version || echo ERROR=$? ; \
+            fi )
+        done
 
     - name: Build, run, and test
       run: |
-        source OpenCoarrays-2.10.2/prerequisites/installations/opencoarrays/2.10.2/setup.sh
-        fpm test --compiler caf --runner "cafrun -n 2" 
+        #source OpenCoarrays-${OC_VERSION}/prerequisites/installations/opencoarrays/${OC_VERSION}/setup.sh
+        fpm test --compiler caf --runner "cafrun -n 2"  ${FPM_FLAGS}
diff --git a/README.md b/README.md
@@ -9,7 +9,7 @@ Despite advances in microscopy, imaging techniques only capture a very small spa
 
 Prerequisites
 -------------
-1. A Fortran 2018 compiler (`gfortran` + [OpenCoarrays])
+1. A Fortran 2018 compiler with multi-image/coarray support (e.g. `gfortran` + [OpenCoarrays])
 2. The Fortran Package Manager
 
 Downloading, Building, and Testing
@@ -44,8 +44,11 @@ export FOR_COARRAY_NUM_IMAGES=4
 fpm test --compiler ifx --profile release --flag "-heap-arrays -coarray"
 ```
 
+Note this requires a working install of Intel MPI.
+
 #### Single-image (serial) execution
 Same as multi-image execution except `FOR_COARRAY_NUM_IMAGES=1`.
+Also requires a working install of Intel MPI.
 
 #### Automatic GPU-based acceleration: _Experimental_
 The following command is listed here for reference while we investigate what appear to be platform-specific compiler issues causing a crashe when automatic GPU-based acceleration is enabled with the required coarray features:

diff --git a/test/subdomain_test_m.F90 b/test/subdomain_test_m.F90
@@ -97,9 +97,13 @@ function concave_laplacian() result(test_diagnosis)
 
     block
       real, parameter :: tolerance = 1.0E-06
+      integer :: nx, ny, nz
       logical internally_zero, concave_at_faces, doubly_concave_at_edges, triply_concave_in_corners, constant_away_from_edges
 
-      associate(me=>this_image(), n_subdomains=>num_images(), nx=>size(lap_f_vals,1), ny=>size(lap_f_vals,2),nz=>size(lap_f_vals,3))
+      nx = size(lap_f_vals,1)
+      ny = size(lap_f_vals,2)
+      nz = size(lap_f_vals,3)
+      associate(me=>this_image(), n_subdomains=>num_images())
         associate(first_zero_in_x => merge(3, 1, me==1), last_zero_in_x => merge(nx-2, nx, me==n_subdomains))
           internally_zero = all(abs(lap_f_vals(first_zero_in_x:last_zero_in_x, 3:ny-2, 3:nz-2)) < tolerance)
         end associate
@@ -197,20 +201,30 @@ function correct_steady_state() result(test_diagnosis)
     end associate
 
     associate(residual => T%values() - T_steady)
+#ifdef __INTEL_COMPILER
+      ! workaround a typecheck defect observed in ifx 2025.2.1
+      test_diagnosis = .all. [(residual .isAtLeast. 0.) .and. (residual .isAtMost. tolerance)]
+#else
       test_diagnosis = .all. ((residual .isAtLeast. 0.) .and. (residual .isAtMost. tolerance))
+#endif
     end associate
   end function
 
   function functional_matches_procedural() result(test_diagnosis)
     type(test_diagnosis_t) test_diagnosis
-    real, parameter :: tolerance = 1.E-06
+    real, parameter :: tolerance = 1.E-05
     integer, parameter :: steps = 1000, n=21
     real, parameter :: alpha = 1.
     real, parameter :: side=1., boundary_val=1., internal_val=2.
 
     associate( T_f => T_functional(), T_p => T_procedural())
       associate(L_infinity_norm => maxval(abs(T_f - T_p)))
+#ifdef __INTEL_COMPILER
+      ! workaround a typecheck defect observed in ifx 2025.2.1
+        test_diagnosis = .all. [T_f .approximates. T_p .within. tolerance]
+#else
         test_diagnosis = .all. (T_f .approximates. T_p .within. tolerance)
+#endif
       end associate
     end associate
 
@@ -249,4 +263,4 @@ function T_procedural()
     end function
 
   end function
-end module subdomain_test_m
+end module subdomain_test_m