gistfile1.txt

---
- name: test nested blocks
  hosts: localhost
  tasks:
    - block:
        - name: first outer level task
          debug:
            msg: first outer level task
        - block:
            - name: first inner level task
              debug:
                msg: first inner level task
            - name: inner task that fails
              fail:
                msg: inner task that fails
            - name: inner task that should never execute
              debug:
                msg: inner task that should never execute
          rescue:
            - name: inner block rescue task
              debug:
                msg: inner block rescue task ansible_failed_result is {{ ansible_failed_result | d("undefined") | to_nice_json }}
            - name: re-raise error
              fail:
                msg: "{{ ansible_failed_result }}"
          always:
            - name: first inner block always task
              debug:
                msg: first inner block always task ansible_failed_result is {{ ansible_failed_result | d("undefined") | to_nice_json }}
        - block:
            - name: second block inner level task
              debug:
                msg: second block inner level task
        - name: second outer level task
          debug:
            msg: second outer level task
      rescue:
        - name: outer block rescue task
          debug:
            msg: outer block rescue task ansible_failed_result is {{ ansible_failed_result | d("undefined") | to_nice_json }}
        - name: check for error message
          assert:
            that: ansible_failed_result.msg == "inner task that fails"


This works:

TASK [inner task that fails] ***************************************************
task path: /home/rmeggins/ansible_sandbox/nested-block.yml:13
fatal: [localhost]: FAILED! => {
    "changed": false
}

MSG:

inner task that fails

TASK [inner block rescue task] *************************************************
task path: /home/rmeggins/ansible_sandbox/nested-block.yml:20
ok: [localhost] => {}

MSG:

inner block rescue task ansible_failed_result is {
    "_ansible_no_log": false,
    "changed": false,
    "failed": true,
    "msg": "inner task that fails"
}

TASK [re-raise error] **********************************************************
task path: /home/rmeggins/ansible_sandbox/nested-block.yml:23
fatal: [localhost]: FAILED! => {
    "changed": false
}

MSG:

{'failed': True, 'msg': 'inner task that fails', '_ansible_no_log': False, 'changed': False}
...
TASK [outer block rescue task] *************************************************
task path: /home/rmeggins/ansible_sandbox/nested-block.yml:38
ok: [localhost] => {}

MSG:

outer block rescue task ansible_failed_result is {
    "_ansible_no_log": false,
    "changed": false,
    "failed": true,
    "msg": "inner task that fails"
}

TASK [check for error message] *************************************************
task path: /home/rmeggins/ansible_sandbox/nested-block.yml:41
ok: [localhost] => {
    "changed": false
}

MSG:

All assertions passed