ci: Minor cleanup

* rename workflow to Stack

* test all branches (provides feedback before opening a PR)

* split into buildenv deps and stack build

* make the deps list more git-friendly; tweak the deps

* use stack from github environment (I've seen the curl fail intermittently)

* use `*.cabal` to minimize diff between our repos

Related: https://github.com/xmonad/X11/pull/75
Related: https://github.com/xmonad/xmonad/issues/283

.github/workflows/stack.yml

@@ -1,10 +1,8 @@
-name: Tests
+name: Stack
 
 on:
-    pull_request:
-    push:
-        branches:
-        - master
+  push:
+  pull_request:
 
 jobs:
   build:
@@ -20,20 +18,29 @@ jobs:
       - name: Clone project
         uses: actions/checkout@v2
 
-      - name: Cache dependencies
+      - name: Install C dependencies
+        run: |
+          set -ex
+          sudo apt install -y \
+            libx11-dev \
+            libxext-dev \
+            libxinerama-dev \
+            libxrandr-dev \
+            libxss-dev \
+            #
+
+      - name: Cache Haskell dependencies
         uses: actions/cache@v2
         with:
           path: ~/.stack
-          key: ${{ runner.os }}-${{ matrix.resolver }}-${{ hashFiles('stack.yaml') }}-${{ hashFiles('xmonad.cabal') }}
+          key: ${{ runner.os }}-${{ matrix.resolver }}-${{ hashFiles('stack.yaml') }}-${{ hashFiles('*.cabal') }}
           restore-keys: |
             ${{ runner.os }}-${{ matrix.resolver }}-${{ hashFiles('stack.yaml') }}-
             ${{ runner.os }}-${{ matrix.resolver }}-
 
-      - name: Build and run tests
-        shell: bash
+      - name: Build and test
         run: |
-            set -ex
-            curl -sSL https://get.haskellstack.org/ | sh -s - -f
-            sudo apt install -y libasound2 libasound2-dev libxrandr-dev libtinfo-dev
-            sudo apt install -y libx11-dev libgmp-dev libxss-dev libxft-dev
-            stack test --fast --no-terminal --resolver=${{ matrix.resolver }}
+          set -ex
+          stack test \
+            --fast --no-terminal \
+            --resolver=${{ matrix.resolver }}