[ ci ] Setup Haskell environment on all platforms

Author: banacorn

.github/workflows/test-linux.yaml

@@ -4,7 +4,7 @@ name: CI (Linux)
 
 on:
   push:
-    branches: [master, ci-*]
+    branches: [master, ci-*, ci]
     tags:
       - 'v*' # Push events to matching v*, i.e. v1.0, v20.15.10
   pull_request:
@@ -18,10 +18,12 @@ jobs:
     - name: 📥 Checkout repository
       uses: actions/checkout@v4
 
-    - name: Determine stack resolver
+    - name: 🔍 Determine stack resolver & GHC
       run: |
         STACK_RESOLVER=$(yq .resolver stack.yaml)
+        GHC_VERSION=$(yq .compiler stack.yaml)
         echo STACK_RESOLVER="${STACK_RESOLVER}" >> "${GITHUB_ENV}"
+        echo GHC_VERSION="${GHC_VERSION}" >> "${GITHUB_ENV}"
 
     # things to be restored:
     # Include STACK_RESOLVER in cache key, otherwise caches accumulate build products for different resolvers.
@@ -55,12 +57,6 @@ jobs:
         # if [[ ! -x ~/.local/bin/stack ]]; then curl -sL https://get.haskellstack.org/stable/linux-x86_64.tar.gz | tar xz --wildcards --strip-components=1 -C ~/.local/bin '*/stack'; chmod a+x ~/.local/bin/stack; fi
         stack --version
 
-    - name: ⏬ Install GHC
-      run: |
-        df -h
-        stack setup --install-ghc
-        df -h
-
     - name: ⏬ Install dependencies
       run: |
         stack build --only-dependencies

.github/workflows/test-mac.yaml

@@ -18,10 +18,12 @@ jobs:
     - name: 📥 Checkout repository
       uses: actions/checkout@v4
 
-    - name: 🔍 Determine stack resolver
+    - name: 🔍 Determine stack resolver & GHC
       run: |
         STACK_RESOLVER=$(yq .resolver stack.yaml)
+        GHC_VERSION=$(yq .compiler stack.yaml)
         echo STACK_RESOLVER="${STACK_RESOLVER}" >> "${GITHUB_ENV}"
+        echo GHC_VERSION="${GHC_VERSION}" >> "${GITHUB_ENV}"
 
     # things to be restored:
     # Include STACK_RESOLVER in cache key, otherwise caches accumulate build products for different resolvers.
@@ -54,23 +56,10 @@ jobs:
       uses: haskell-actions/setup@v2
       id: setup-haskell
       with:
-        ghc-version: '9.2.8'
+        ghc-version: ${{ env.GHC_VERSION }}
         enable-stack: true
         stack-version: 'latest'
 
-    # - name: ⏬ Install stack
-    #   run: |
-    #     # mkdir -p ~/.local/bin
-    #     # export PATH=~/.local/bin:$PATH
-    #     ## Stack is preinstalled on the GHA runners
-    #     # brew install gnu-tar; curl -sL https://get.haskellstack.org/stable/osx-x86_64.tar.gz | gtar xz --wildcards --strip-components=1 -C ~/.local/bin '*/stack'; chmod a+x ~/.local/bin/stack
-    #     # if [[ ! -x ~/.local/bin/stack ]]; then brew install gnu-tar; curl -sL https://get.haskellstack.org/stable/osx-x86_64.tar.gz | gtar xz --wildcards --strip-components=1 -C ~/.local/bin '*/stack'; chmod a+x ~/.local/bin/stack; fi
-    #     stack --version
-
-    # - name: ⏬ Install GHC
-    #   run: |
-    #     stack setup --install-ghc
-
     - name: ⏬ Install dependencies
       run: |
         stack build --only-dependencies

.github/workflows/test-windows.yaml

@@ -25,16 +25,18 @@ jobs:
     - name: 🏗 Install yq
       uses: frenck/action-setup-yq@v1
 
-    - name: Determine stack root and resolver
+    - name: 🔍 Determine stack root and resolver and GHC
       ## 2023-11-21 https://github.com/commercialhaskell/stack/issues/6340
       ## Asking stack for the stack root unfortunately does not work
       ## if stack is not fully operational (meaning e.g. that GHC is installed)
       ## so we hardcode its location instead.
       run: |
         STACK_ROOT="C:/Users/runneradmin/AppData/Local/Programs/stack/x86_64-windows"
         STACK_RESOLVER=$(yq .resolver stack.yaml)
+        GHC_VERSION=$(yq .compiler stack.yaml)
         echo STACK_ROOT="${STACK_ROOT}"         >> "${GITHUB_ENV}"
         echo STACK_RESOLVER="${STACK_RESOLVER}" >> "${GITHUB_ENV}"
+        echo GHC_VERSION="${GHC_VERSION}" >> "${GITHUB_ENV}"
       # run: |
       #   STACK_ROOT="$(stack --system-ghc --no-install-ghc path --stack-root || echo "C:/Users/runneradmin/AppData/Local/Programs/stack/x86_64-windows")"
       #   echo "STACK_ROOT = ${STACK_ROOT}"
@@ -64,22 +66,22 @@ jobs:
 
     # actions
 
-    - name: ⏬ Install stack
-      ## Stack is preinstalled on GHA runners.
-      #
-      #if: steps.stack-programs-dir.outputs.cache-hit != 'true'
-      # this step is needed to get stack.exe into PATH, for now
-        # curl -sL https://get.haskellstack.org/stable/windows-x86_64.zip -o stack.zip
-        # 7z x stack.zip stack.exe
-      run: |
-        which stack
-        stack --version
-
-    - name: ⏬ Install GHC
-      # if: steps.stack-programs-dir.outputs.cache-hit != 'true'
-      # set PATH=C:\Users\runneradmin\AppData\Local\Programs\stack\local\bin;%PATH%
-      run: |
-        stack --no-terminal setup --install-ghc
+    # - name: ⏬ Install stack
+    #   ## Stack is preinstalled on GHA runners.
+    #   #
+    #   #if: steps.stack-programs-dir.outputs.cache-hit != 'true'
+    #   # this step is needed to get stack.exe into PATH, for now
+    #     # curl -sL https://get.haskellstack.org/stable/windows-x86_64.zip -o stack.zip
+    #     # 7z x stack.zip stack.exe
+    #   run: |
+    #     which stack
+    #     stack --version
+
+    # - name: ⏬ Install GHC
+    #   # if: steps.stack-programs-dir.outputs.cache-hit != 'true'
+    #   # set PATH=C:\Users\runneradmin\AppData\Local\Programs\stack\local\bin;%PATH%
+    #   run: |
+    #     stack --no-terminal setup --install-ghc
 
     - name: Install the icu library
       run: |