Exit with warnings.

.github/workflows/docs.yml

@@ -43,7 +43,7 @@ jobs:
           egrep "WARNING:" build-output.txt | sort | uniq | \
             awk 'BEGIN{i=0}{print $0}{i++}END{print "Warnings: "i}' > build-output-warnings.txt
           cat build-output-warnings.txt
-          #exit $(tail -n 1 build-output-warnings.txt | awk '{print $2}')
+          exit $(tail -n 1 build-output-warnings.txt | awk '{print $2}')
       - name: Deploy
         if: github.event_name == 'push'
         uses: JamesIves/github-pages-deploy-action@releases/v3