Add Spack test to Actions CI (#218)

* Add Spack CI test

* Update comment

.github/workflows/spack.yml

@@ -0,0 +1,88 @@
+name: Spack build
+
+on:
+  # Uncomment the below 'push' to trigger on push
+  # push:
+  #  branches:
+  #    - "**"
+  schedule:
+    # '*' is a special character in YAML, so string must be quoted
+    - cron: "0 2 * * WED"
+  workflow_dispatch:
+    inputs:
+      spack_repo:
+        description: "Spack repository to test"
+        default: "spack/spack"
+        type: string
+      spack_ref:
+        description: "Spack repository branch/tag to test"
+        default: "develop"
+        type: string
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    container: ubuntu:latest
+    steps:
+      - name: Get Spack
+        if: github.event_name != 'workflow_dispatch'
+        uses: actions/checkout@v4
+        with:
+          path: ./spack
+          repository: spack/spack
+      - name: Get Spack
+        if: github.event_name == 'workflow_dispatch'
+        uses: actions/checkout@v4
+        with:
+          path: ./spack
+          repository: ${{ github.event.inputs.spack_repo }}
+          ref: ${{ github.event.inputs.spack_ref }}
+
+      - name: Install Spack requirements
+        run: |
+          apt-get -y update
+          apt-get install -y bzip2 curl file git gzip make patch python3-minimal tar xz-utils
+          apt-get install -y g++ gfortran  # compilers
+
+      - name: Insall UFL development version via Spack
+        run: |
+          . ./spack/share/spack/setup-env.sh
+          spack env create main
+          spack env activate main
+          spack add py-fenics-ufl@main
+          spack install
+      - name: Get UFL code (to access test files)
+        uses: actions/checkout@v4
+        with:
+          path: ./ufl-main
+      - name: Run tests (development version)
+        run: |
+          . ./spack/share/spack/setup-env.sh
+          spack env create main-test
+          spack env activate main-test
+          spack add py-fencis-ufl@main py-pytest
+          cd ufl-main/test/
+          pytest -n auto .
+
+      - name: Install UFL release version via Spack
+        run: |
+          . ./spack/share/spack/setup-env.sh
+          spack env create release
+          spack env activate release
+          spack add py-fenics-ufl
+          spack install
+      - name: Get UFL release code (to access test files)
+        uses: actions/checkout@v4
+        with:
+          ref: v2023.2.0
+          # ref: v${{ github.event.inputs.spack_branch }}
+          path: ./ufl-release
+      - name: Run tests (release version)
+        run: |
+          . ./spack/share/spack/setup-env.sh
+          spack env create release-test
+          spack env activate release-test
+          spack add py-fenics-ufl py-pytest
+          spack install
+          cd ufl-release/test/
+          pytest -n auto .