First attempt at github actions for stack

.github/workflows/build-all-versions.yml

@@ -0,0 +1,95 @@
+# Based on the template here: https://kodimensional.dev/github-actions
+name: Build with stack and cabal
+
+# Trigger the workflow on push or pull request, but only for the master branch
+on:
+  pull_request:
+  push:
+    branches: [master]
+
+jobs:
+  cabal:
+    name: ${{ matrix.os }} / ghc ${{ matrix.ghc }}
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os: [ubuntu-latest, macOS-latest, windows-latest]
+        cabal: ["3.2"]
+        ghc:
+          - "8.6.5"
+          - "8.8.3"
+          - "8.10.1"
+        exclude:
+          - os: macOS-latest
+            ghc: 8.8.3
+          - os: macOS-latest
+            ghc: 8.6.5
+          - os: windows-latest
+            ghc: 8.8.3
+          - os: windows-latest
+            ghc: 8.6.5
+
+    steps:
+    - uses: actions/checkout@v2
+      if: github.event.action == 'opened' || github.event.action == 'synchronize' || github.event.ref == 'refs/heads/master'
+
+    - uses: actions/setup-haskell@v1.1.1
+      id: setup-haskell-cabal
+      name: Setup Haskell
+      with:
+        ghc-version: ${{ matrix.ghc }}
+        cabal-version: ${{ matrix.cabal }}
+
+    - name: Freeze
+      run: |
+        cabal freeze
+
+    - uses: actions/cache@v1
+      name: Cache ~/.cabal/store
+      with:
+        path: ${{ steps.setup-haskell-cabal.outputs.cabal-store }}
+        key: ${{ runner.os }}-${{ matrix.ghc }}
+        # key: ${{ runner.os }}-${{ matrix.ghc }}-${{ hashFiles('cabal.project.freeze') }}
+
+    - name: Build
+      run: |
+        cabal configure --enable-tests --enable-benchmarks --test-show-details=direct
+        cabal build all
+
+    # - name: Test
+    #   run: |
+    #     cabal test all
+
+  stack:
+    name: stack / ghc ${{ matrix.ghc }}
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        stack: ["2.3.3"]
+        ghc: ["7.10.3","8.0.2", "8.2.2", "8.4.4", "8.6.5", "8.8.4"]
+        # ghc: ["8.8.3"]
+
+    steps:
+    - uses: actions/checkout@v2
+      if: github.event.action == 'opened' || github.event.action == 'synchronize' || github.event.ref == 'refs/heads/master'
+
+    - uses: actions/setup-haskell@v1.1
+      name: Setup Haskell Stack
+      with:
+        # ghc-version: ${{ matrix.ghc }}
+        stack-version: ${{ matrix.stack }}
+
+    - uses: actions/cache@v1
+      name: Cache ~/.stack
+      with:
+        path: ~/.stack
+        key: ${{ runner.os }}-${{ matrix.ghc }}-stack
+
+    - name: Build
+      run: |
+        stack build --system-ghc --stack-yaml stack-ghc${{ matrix.ghc }}.yaml
+        # stack build --system-ghc --test --bench --no-run-tests --no-run-benchmarks
+
+    # - name: Test
+    #   run: |
+    #     stack test --system-ghc