Premerge space adjustment, and missing quotes. (#1695)

split space between system and build path

.github/workflows/premerge.yml

@@ -26,11 +26,18 @@ jobs:
     - name: Maximize build space
       uses: easimon/maximize-build-space@master
       with:
-        root-reserve-mb: 512
+        root-reserve-mb: 30720
         swap-size-mb: 1024
         remove-dotnet: 'true'
         remove-android: 'true'
         remove-haskell: ' true'
+        remove-codeql: 'true'
+    - name: Provide additional free space
+      run: |
+        # Workaround to provide additional free space for builds
+        #   https://github.com/actions/virtual-environments/issues/2840
+        sudo rm -rf /usr/share/dotnet /usr/local/lib/android /opt/ghc /usr/local/share/boost "$AGENT_TOOLSDIRECTORY"
+        df -h
     - name: Login to GitHub Container Registry
       uses: docker/login-action@v2
       with:
@@ -41,7 +48,7 @@ jobs:
     - name: Define BRANCH, COMMIT and G_ACCOUNT in environment
       run: |
         echo "G_ACCOUNT=${GITHUB_REPOSITORY_OWNER,,}" >> $GITHUB_ENV
-        if [[ -z ${{ env.BRANCH }} ]]; then
+        if [[ -z "${{ env.BRANCH }}" ]]; then
           echo "BRANCH=${GITHUB_HEAD_REF}" >> $GITHUB_ENV
           echo "COMMIT=$(git rev-parse --short "$GITHUB_SHA")" >> $GITHUB_ENV
         else