Use haskell-actions

.github/workflows/benchmarking.yml

@@ -7,35 +7,64 @@ on:
 permissions:
   contents: read
 
+# INFO: The following configuration block ensures that only one build runs per branch,
+# which may be desirable for projects with a costly build process.
+# Remove this block from the CI workflow to let each CI job run to completion.
+concurrency:
+  group: build-${{ github.ref }}
+  cancel-in-progress: true
+
 jobs:
   build:
-
-    runs-on: ubuntu-latest
+    name: GHC ${{ matrix.ghc-version }} on ${{ matrix.os }}
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-latest]
+        ghc-version: ['9.6.5']
 
     steps:
-    - uses: actions/checkout@v4
-    - uses: actions/setup-haskell@v1
-      with:
-        ghc-version: '9.6.5'
-        cabal-version: '3.10.3.0'
-
-    - name: Cache
-      uses: actions/cache@v3
-      env:
-        cache-name: cache-cabal
-      with:
-        path: ~/.cabal
-        key: ${{ runner.os }}-build-${{ env.cache-name }}-${{ hashFiles('**/*.cabal') }}-${{ hashFiles('**/cabal.project') }}
-        restore-keys: |
-          ${{ runner.os }}-build-${{ env.cache-name }}-
-          ${{ runner.os }}-build-
-          ${{ runner.os }}-
-
-    - name: Install dependencies
-      run: |
-        cabal update
-        cabal build --only-dependencies --enable-tests --enable-benchmarks
-    - name: Build
-      run: cabal build --enable-tests --enable-benchmarks all
-    - name: Run benchmarking
-      run: cabal run
+      - uses: actions/checkout@v4
+
+      - name: Set up GHC ${{ matrix.ghc-version }}
+        uses: haskell-actions/setup@v2
+        id: setup
+        with:
+          ghc-version: ${{ matrix.ghc-version }}
+          # Defaults, added for clarity:
+          cabal-version: 'latest'
+          cabal-update: true
+
+      - name: Configure the build
+        run: |
+          cabal configure --enable-tests --enable-benchmarks --disable-documentation
+          cabal build all --dry-run
+        # The last step generates dist-newstyle/cache/plan.json for the cache key.
+
+      - name: Restore cached dependencies
+        uses: actions/cache/restore@v4
+        id: cache
+        env:
+          key: ${{ runner.os }}-ghc-${{ steps.setup.outputs.ghc-version }}-cabal-${{ steps.setup.outputs.cabal-version }}
+        with:
+          path: ${{ steps.setup.outputs.cabal-store }}
+          key: ${{ env.key }}-plan-${{ hashFiles('**/plan.json') }}
+          restore-keys: ${{ env.key }}-
+
+      - name: Install dependencies
+        # If we had an exact cache hit, the dependencies will be up to date.
+        if: steps.cache.outputs.cache-hit != 'true'
+        run: cabal build all --only-dependencies
+
+      # Cache dependencies already here, so that we do not have to rebuild them should the subsequent steps fail.
+      - name: Save cached dependencies
+        uses: actions/cache/save@v4
+        # If we had an exact cache hit, trying to save the cache would error because of key clash.
+        if: steps.cache.outputs.cache-hit != 'true'
+        with:
+          path: ${{ steps.setup.outputs.cabal-store }}
+          key: ${{ steps.cache.outputs.cache-primary-key }}
+
+      - name: Bench
+        run: cabal run