WIP - caching sources separately

Author: Anton-Latukha

.github/workflows/cache-deps.yml

@@ -73,14 +73,21 @@ jobs:
           echo "package floskell" >> cabal.project
           echo "  ghc-options: -O0" >> cabal.project
 
+      - name: Cache Cabal
+        uses: actions/cache@v2
+        env:
+          cache-name: hackage-sources
+        with:
+          path: ${{ env.CABAL_PKGS_DIR }}
+          key: v2-${{ runner.os }}-${{ matrix.ghc }}-hackage-sources-${{ hashFiles('cabal.project') }}
+          restore-keys: v2-${{ runner.os }}-${{ matrix.ghc }}-hackage-sources-
+
       - name: Cache Cabal
         uses: actions/cache@v2
         env:
           cache-name: cache-cabal
         with:
-          path: |
-            ${{ steps.HaskEnvSetup.outputs.cabal-store }}
-            ${{ env.CABAL_PKGS_DIR }}
+          path: ${{ steps.HaskEnvSetup.outputs.cabal-store }}
           key: v2-${{ runner.os }}-${{ matrix.ghc }}-build-${{ hashFiles('cabal.project') }}
           restore-keys: v2-${{ runner.os }}-${{ matrix.ghc }}-build-