Create STACK_ROOT before writing config

Author: jneira

.azure/windows-installhs-stack.yml

@@ -14,7 +14,7 @@ jobs:
       cacheHitVar: CACHE_RESTORED
     displayName: "Cache stack-root"
   - bash: |
-      mkdir -p $STACK_ROOT
+      mkdir -p "$STACK_ROOT"
       tar -vxzf .azure-cache/stack-root.tar.gz -C /d
       mkdir -p .stack-work
       tar -vxzf .azure-cache/stack-work.tar.gz
@@ -25,7 +25,8 @@ jobs:
   - bash: |
       curl -sSkL http://www.stackage.org/stack/windows-x86_64 -o /usr/bin/stack.zip
       unzip -o /usr/bin/stack.zip -d /usr/bin/
-      echo "local-programs-path: D:/bin/stack" > $STACK_ROOT/config.yaml
+      mkdir -p "$STACK_ROOT"
+      echo "local-programs-path: D:/bin/stack" > "$STACK_ROOT/config.yaml"
     displayName: Install stack
   - bash: |
       source .azure/windows-stack.bashrc