test case for 78805

inventory

[pause_group0]
pause0
pause1
pause2

[pause_group1]
pause3
pause4
pause5

[pause_group2]
pause6
pause7
pause8

[pause_group3]
pause9
pause10
pause11

[pause_group4]
pause12
pause13
pause14

[no_pause_group]
host0
host1
host2
host3
host4
host5
host6
host7
host8
host9
host10
host11
host12
host13
host14
host15
host16
host17
host18
host19
host20
host21
host22
host23
host24
host25
host26
host27
host28
host29
host30

[pause_group0:vars]
sleep=1

[pause_group1:vars]
sleep=2

[pause_group2:vars]
sleep=3

[pause_group3:vars]
sleep=4

[pause_group4:vars]
sleep=5

[pause:children]
pause_group0
pause_group1
pause_group2
pause_group3
pause_group4

[all:children]
pause
no_pause_group

[all:vars]
run_count=0
ansible_host=127.0.0.1
ansible_connection=local

playbook.yml

- hosts: all
  strategy: free
  gather_facts: no
  tasks:
    - name: delay some hosts
      wait_for:
        timeout: "{{ hostvars[inventory_hostname]['sleep'] }}"
      when: inventory_hostname in groups['pause']

    - name: Include 0
      include_tasks:
        file: test_include.yml
      vars:
        some_var: 0

    - name: add a random pause 
      wait_for:
        timeout: 1
      when: 10 | random > 5

    - name: Include 1
      include_tasks:
        file: test_include.yml
      vars:
        some_var: 1

    - name: Include 2
      include_tasks:
        file: test_include.yml
      vars:
        some_var: 2

    - name: Include 3
      include_tasks:
        file: test_include.yml
      vars:
        some_var: 3

    - name: add a random pause
      wait_for:
        timeout: 1
      when: 10 | random > 5

    - name: Include 4
      include_tasks:
        file: test_include.yml
      vars:
        some_var: 4

    - name: Include 5
      include_tasks:
        file: test_include.yml
      vars:
        some_var: 5

    - name: Include 6
      include_tasks:
        file: test_include.yml
      vars:
        some_var: 6

    - name: add a random pause
      wait_for:
        timeout: 1
      when: 10 | random > 5

    - name: Include 7
      include_tasks:
        file: test_include.yml
      vars:
        some_var: 7

    - name: Include 8
      include_tasks:
        file: test_include.yml
      vars:
        some_var: 8

    - name: Include 9
      include_tasks:
        file: test_include.yml
      vars:
        some_var: 9

test_include.yml

- debug:
    msg: "{{ some_var }} == {{ hostvars[inventory_hostname]['run_count'] }}"

- assert:
    that: hostvars[inventory_hostname]['run_count'] | int == some_var

- set_fact:
    run_count: "{{ hostvars[inventory_hostname]['run_count'] | int + 1 }}"