CI (MSYS2): Update location of compiler cache.

.github/workflows/dynamic_arch.yml

@@ -217,11 +217,16 @@ jobs:
       - name: Checkout repository
         uses: actions/checkout@v3
 
+      - name: Prepare ccache
+        # Get cache location of ccache
+        id: ccache-prepare
+        run: |
+          echo "ccachedir=$(cygpath -m $(ccache -k cache_dir))" >> $GITHUB_OUTPUT
+
       - name: Compilation cache
         uses: actions/cache@v3
         with:
-          # It looks like this path needs to be hard-coded.
-          path: C:/msys64/home/runneradmin/.ccache
+          path: ${{ steps.ccache-prepare.outputs.ccachedir }}
           # We include the commit sha in the cache key, as new cache entries are
           # only created if there is no existing entry for the key yet.
           key: ccache-msys2-${{ matrix.msystem }}-${{ matrix.idx }}-${{ matrix.build-type }}-${{ github.ref }}-${{ github.sha }}
@@ -234,9 +239,10 @@ jobs:
         # Limit the maximum size and switch on compression to avoid exceeding the total disk or cache quota.
         run: |
           which ccache
-          test -d ~/.ccache || mkdir -p ~/.ccache
-          echo "max_size = 250M" > ~/.ccache/ccache.conf
-          echo "compression = true" >> ~/.ccache/ccache.conf
+          test -d ${{ steps.ccache-prepare.outputs.ccachedir }} || mkdir -p ${{ steps.ccache-prepare.outputs.ccachedir }}
+          echo "max_size = 250M" > ${{ steps.ccache-prepare.outputs.ccachedir }}/ccache.conf
+          echo "compression = true" >> ${{ steps.ccache-prepare.outputs.ccachedir }}/ccache.conf
+          ccache -p
           ccache -s
           echo $HOME
           cygpath -w $HOME