title: Ansible Task failing with when condition
body: <p>My Ansible Task is getting failed with false when condition ( Task should fail only if "when" condition is true)</p>
  
  <p>My Playbook</p>
  
  <pre><code>    - name: 'Check if any task is existing'
        command: aws ecs list-tasks --cluster mycluster --query length(taskArns[*])
        register: ecs_tasks
  
      - name: 'Fail playbook if some task is already existing in cluster'
        fail:
          msg: "There is already an existing task in mycluster"
        when: ecs_tasks.stdout != 0
  
      - name: 'Create Ranger task'
        command: create ECS task
        register: ecs_task
  
  </code></pre>
  
  <p>Output</p>
  
  <pre><code>    "stderr": "", 
      "stderr_lines": [], 
      "stdout": "0", 
      "stdout_lines": [
          "0"
      ]
      }
  
      TASK [Fail playbook if some task is already existing in cluster] ***************
      task path: /home/somepath/Task.yml:35
      fatal: [127.0.0.1]: FAILED! =&gt; {
      "changed": false, 
      "msg": "There is already an existing task in mycluster"
      }
  
      PLAY RECAP *********************************************************************
  09:09:38  127.0.0.1                  : ok=5    changed=4    unreachable=0    failed=1    skipped=0    rescued=0    ignored=0    
  </code></pre>
  
  <p>Is it some issue with my when Condition format, because i have tried various conditions like >0 and >=1, but no luck as it is still failing for (No tasks exists in my ECS cluster) and also
  AWS CLI Command returns</p>
  
  <pre><code>aws ecs list-tasks --cluster mycluster --query length(taskArns[*])
  0
  </code></pre>