add

.github/workflows/ci.yml

@@ -283,3 +283,8 @@ jobs:
         channel: '#ci'
         isCompactMode: true
         url: ${{ secrets.SLACK_WEBHOOK_URL }}
+
+    - name: Check whether workspace is clean
+      run: |
+        STATUS=`git status --porcelain`
+        if [ -z "$STATUS" ]; then exit 0; else exit 1; fi