Change to use lineinfile,

playbook/roles/erp5-standalone/tasks/main.yml

@@ -19,7 +19,7 @@
     copy: src=erp5-startup dest=/usr/local/bin/erp5-startup mode=755
   
   - name: Add to rc.local
-    shell: sed -i -e '$i \bash /usr/local/bin/erp5-startup &\n' /etc/rc.local
+    lineinfile: dest=/etc/rc.local insertbefore=BOF line='bash /usr/local/bin/erp5-startup &'
     when: grep -Fxq "/usr/local/bin/erp5-startup" /etc/rc.local == 0
 
   - name: Get slapos.playbook directory name