Update CI to latest GHC and action versions, modernize caching (#448)

* Update CI to latest GHC and action versions, modernize caching

- separate caching into restore and save step
- always save cache even if build failed (speeds up next attempt)
- use build plan rather than freeze file as cache key

* Use andreasabel/fix-whitespace-action

* Update requirements.txt for doc building (Sphinx)

* Remove if on actions/checkout (makes no sense)

* Deploy docs only when merged into master

Author: andreasabel

.github/workflows/ci.yml

@@ -3,6 +3,16 @@ name: CI
 # Trigger the workflow on push or pull request, but only for the master branch
 on:
   pull_request:
+    paths:
+      - 'lib/**'
+      - 'src/**'
+      - 'test/**'
+      - 'lib/base/base.agda-lib'
+      - 'agda2hs.cabal'
+      - 'cabal.project'
+      - 'Makefile'
+      - '.github/workflows/**.yml'
+    branches: [master]
   push:
     paths:
       - 'lib/**'
@@ -22,12 +32,11 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest]   # macOS-latest, windows-latest
-        cabal: [3.10.3]
-        deploy-ghc: [9.6.6]
-        ghc: [9.4.8, 9.6.6, 9.8.2, 9.10.1]
+        cabal: [3.14.2.0]
+        deploy-ghc: [9.6.7]
+        ghc: [9.6.7, 9.8.4, 9.10.3, 9.12.2]
     steps:
-    - uses: actions/checkout@v3
-      if: github.event.action == 'opened' || github.event.action == 'synchronize' || github.event.ref == 'refs/heads/master'
+    - uses: actions/checkout@v6
 
     # Takes care of ghc and cabal. See https://github.com/haskell/actions.
     - uses: haskell-actions/setup@v2
@@ -37,42 +46,64 @@ jobs:
         ghc-version: ${{ matrix.ghc }}
         cabal-version: ${{ matrix.cabal }}
 
-    # Generate a cabal.project.freeze file with all dependencies. We use the
-    # hash of this as the cache key, so when a dependency changes we upload a
-    # new cache.
-    - name: Freeze
-      run: cabal freeze
+    # Andreas, 2025-11-28: Since the freeze file contains a timestamp of the Hackage index
+    # and the index changes several times a day,
+    # the freeze file is not very useful as a cache key.
+    # Instead, use the plan.json file (see below).
+    # # Generate a cabal.project.freeze file with all dependencies. We use the
+    # # hash of this as the cache key, so when a dependency changes we upload a
+    # # new cache.
+    # - name: Freeze
+    #   run: cabal freeze
 
-    # Install fix-whitespace since we need it for tests.
-    # This is done after the freeze to make sure we re-use the packages
-    - name: Install fix-whitespace
+    - name: Configure the build plan
       run: |
-        echo "import: cabal.project" > cabal.project.ci
-        cabal install fix-whitespace --project-file=cabal.project.ci
+        cabal build --dry-run
+      # cabal build --dry-run creates dist-newstyle/cache/plan.json
+
+    # Andreas, 2025-11-28, AIM XLI, use fix-whitespace-action
+    # # Install fix-whitespace since we need it for tests.
+    # # This is done after the freeze to make sure we re-use the packages
+    # - name: Install fix-whitespace
+    #   run: |
+    #     echo "import: cabal.project" > cabal.project.ci
+    #     cabal install fix-whitespace --project-file=cabal.project.ci
 
     # Cache the contents of ~/.cabal/store to avoid rebuilding dependencies for
     # every build. `restore-keys` makes it use the latest cache even if the
     # fingerprint doesn't match, so we don't need to start from scratch every
     # time a dependency changes.
-    - uses: actions/cache@v3
-      name: Cache ~/.cabal/store
+    - uses: actions/cache/restore@v4
+      name: Restore cached ~/.cabal/store
+      id: cache
       with:
         path:         ${{ steps.setup-haskell-cabal.outputs.cabal-store }}
-        key:          ${{ runner.os }}-${{ matrix.ghc }}-${{ hashFiles('cabal.project.freeze') }}
+        # The freeze file is a bad key, use dist-newstyle/cache/plan.json instead.
+        # key:          ${{ runner.os }}-${{ matrix.ghc }}-${{ hashFiles('cabal.project.freeze') }}
+        key:          ${{ runner.os }}-${{ matrix.ghc }}-${{ hashFiles('**/plan.json') }}
         restore-keys: ${{ runner.os }}-${{ matrix.ghc }}-
 
+    - name: Run fix-whitespace
+      uses: andreasabel/fix-whitespace-action@v1
+
     - name: Run test suite
-      run: make test && git diff --exit-code
+      run: make test-on-CI && git diff --exit-code
 
     - name: Generate Prelude HTML
       if: ${{ (matrix.ghc == matrix.deploy-ghc) && (github.ref == 'refs/heads/master') }}
       run: make libHtml
 
     - name: Deploy Prelude HTML
       if: ${{ (matrix.ghc == matrix.deploy-ghc) && (github.ref == 'refs/heads/master') }}
-      uses: peaceiris/actions-gh-pages@v3
+      uses: peaceiris/actions-gh-pages@v4
       with:
         github_token: ${{ secrets.GITHUB_TOKEN }}
         publish_dir: html
         destination_dir: lib
 
+    - uses: actions/cache/save@v4
+      name: Cache ~/.cabal/store
+      if: always() && steps.cache.outputs.cache-hit != 'true'
+      with:
+        path: ${{ steps.setup-haskell-cabal.outputs.cabal-store }}
+        key:  ${{ steps.cache.outputs.cache-primary-key }}

.github/workflows/docs.yml

@@ -6,6 +6,10 @@ on:
   push:
     branches: [master]
 
+  # Runs on PRs targeting the default branch
+  pull_request:
+    branches: [master]
+
   # Allows you to run this workflow manually from the Actions tab
   workflow_dispatch:
 
@@ -19,7 +23,7 @@ jobs:
   deploy:
     strategy:
       matrix:
-        python-version: ["3.10.8"]
+        python-version: ["3.14"]
 
     env:
       DOCS_DIR: docs
@@ -28,21 +32,27 @@ jobs:
 
     runs-on: ubuntu-latest
     steps:
+
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v6
+
       - name: Set up Python ${{ matrix.python-version }}
-        uses: actions/setup-python@v4
+        uses: actions/setup-python@v6
         with:
           python-version: ${{ matrix.python-version }}
+
       - name: Install dependencies
         run: |
           pip install -r ${{ env.DOCS_DIR }}/requirements.txt
+
       - name: Build User Manual in HTML
         run: |
           cd ${{ env.DOCS_DIR }}
           make html
+
       - name: Deploy to GitHub Pages
-        uses: peaceiris/actions-gh-pages@v3
+        uses: peaceiris/actions-gh-pages@v4
+        if: github.ref == 'refs/heads/master'
         with:
           github_token: ${{ secrets.GITHUB_TOKEN }}
           publish_dir: ${{ env.DOCS_BUILD_HTML_DIR }}

.github/workflows/nix-ci.yml

@@ -33,8 +33,8 @@ jobs:
           - pretty: "Typecheck with Agda"
             derivation: containers-lib
     steps:
-    - uses: actions/checkout@v3
-    - uses: nixbuild/nix-quick-install-action@v30
+    - uses: actions/checkout@v6
+    - uses: nixbuild/nix-quick-install-action@v34
       with:
         nix_conf: |
           keep-env-derivations = true
@@ -50,8 +50,8 @@ jobs:
     name: "Test building inside a nix shell"
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v3
-    - uses: nixbuild/nix-quick-install-action@v30
+    - uses: actions/checkout@v6
+    - uses: nixbuild/nix-quick-install-action@v34
       with:
         nix_conf: |
           keep-env-derivations = true

Makefile

@@ -1,4 +1,4 @@
-.PHONY : install agda repl libHtml test testContainers testHtml golden docs
+.PHONY : install agda repl libHtml testContainers test test-on-CI testHtml golden clean docs
 FILES = $(shell find src -type f)
 
 build :
@@ -23,7 +23,9 @@ test/agda2hs : $(FILES)
 testContainers:
 	cd ./lib/containers && ./generate-haskell.sh && cabal build containers-prop
 
-test : checkWhitespace test/agda2hs testContainers
+test : checkWhitespace test-on-CI
+
+test-on-CI : test/agda2hs testContainers
 	make -C test
 
 testHtml : test/agda2hs

docs/requirements.txt

@@ -1,4 +1,4 @@
-sphinx==5.3.0
-sphinx_rtd_theme==1.1.1
-readthedocs-sphinx-search==0.1.2
-myst_parser==0.18.1
+sphinx==8.2.3
+sphinx_rtd_theme==3.0.2
+readthedocs-sphinx-search==0.3.2
+myst-parser==4.0.1