playbook variables defined in includes from vars_files: not usable throughout the playbook., regression from 1.7.2 to 1.8.2

[Jan Tryggveson]

The almost minimal example below works fine in ansible 1.7.2 but does not give same and expected result in 1.8.2.

In short what this script is doing is to increment a counter in the hosts_names.yml file whenever the variable system_upgrade equals 'True'.
This works fine with ansible 1.7.2 but on 1.8.2 a default value I use for the variable that should be used if the file hosts_names.yml doesn't exist partly take precedance over the value read from the file.

 The playbook is invoked with eighter of these two command lines:
ansible-playbook sample.yml -u msp --extra-vars "userid=msp system_upgrade=False"
ansible-playbook sample.yml -u msp --extra-vars "userid=msp system_upgrade=True"

If someone interested I can supply a tar file with the complete sample project.

---
  #
- hosts: 127.0.0.1
# user will be overridden by user from command line
  user: "{{ userid }}"
  gather_facts: no

  vars_files:
    - - "{{ hosts_names_vars_file }}"
      - "{{ default_hosts_names_vars_file }}"
   
  vars:
    #
    # Global System Configuration
    #
    userid: root
    hosts_names_vars_file: "./hosts_names.yml"
    default_hosts_names_vars_file: "./default_hosts_names.yml"

  pre_tasks:
    - local_action: debug msg="Last deployment_index = {{ deployment_index_h | default(99) | int }}"

  roles:
     - { role: sample }

Output from first four times I  run on ansible 1.8.2, After that the same but with ansible 1.7.2:

ansible-playbook sample.yml -u msp --extra-vars "userid=msp system_upgrade=False"

PLAY [127.0.0.1] **************************************************************
127.0.0.1: not importing file: /home/msp/error/hosts_names.yml

TASK: [debug msg="Last deployment_index = 99"] ********************************
ok: [127.0.0.1 -> 127.0.0.1] => {
    "msg": "Last deployment_index = 99"
}

TASK: [sample | Generate hosts_names in current dir] **************************
changed: [127.0.0.1 -> 127.0.0.1]

TASK: [sample | debug msg="Index = 3 0"] **************************************
ok: [127.0.0.1] => {
    "msg": "Index = 3 0"
}

PLAY RECAP ********************************************************************
127.0.0.1                  : ok=3    changed=1    unreachable=0    failed=0  

msp@msp-precision-02:~/error$
ansible-playbook sample.yml -u msp --extra-vars "userid=msp system_upgrade=False"

PLAY [127.0.0.1] **************************************************************

TASK: [debug msg="Last deployment_index = 99"] ********************************
ok: [127.0.0.1 -> 127.0.0.1] => {
    "msg": "Last deployment_index = 0"
}

TASK: [sample | Generate hosts_names in current dir] **************************
ok: [127.0.0.1 -> 127.0.0.1]

TASK: [sample | debug msg="Index = 3 0"] **************************************
ok: [127.0.0.1] => {
    "msg": "Index = 3 0"
}

PLAY RECAP ********************************************************************
127.0.0.1                  : ok=3    changed=0    unreachable=0    failed=0  

ansible-playbook sample.yml -u msp --extra-vars "userid=msp system_upgrade=True"

PLAY [127.0.0.1] **************************************************************

TASK: [debug msg="Last deployment_index = 99"] ********************************
ok: [127.0.0.1 -> 127.0.0.1] => {
    "msg": "Last deployment_index = 0"
}

TASK: [sample | Generate hosts_names in current dir] **************************
changed: [127.0.0.1 -> 127.0.0.1]

TASK: [sample | debug msg="Index = 3 0"] **************************************
ok: [127.0.0.1] => {
    "msg": "Index = 3 0"
}

PLAY RECAP ********************************************************************
127.0.0.1                  : ok=3    changed=1    unreachable=0    failed=0  

ansible-playbook sample.yml -u msp --extra-vars "userid=msp system_upgrade=True"

PLAY [127.0.0.1] **************************************************************

TASK: [debug msg="Last deployment_index = 99"] ********************************
ok: [127.0.0.1 -> 127.0.0.1] => {
    "msg": "Last deployment_index = 1"
}

TASK: [sample | Generate hosts_names in current dir] **************************
ok: [127.0.0.1 -> 127.0.0.1]

TASK: [sample | debug msg="Index = 3 0"] **************************************
ok: [127.0.0.1] => {
    "msg": "Index = 3 0"
}

PLAY RECAP ********************************************************************
127.0.0.1                  : ok=3    changed=0    unreachable=0    failed=0  
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

Same but with ansible 1.7.2
 ansible-playbook sample.yml -u msp --extra-vars "userid=msp system_upgrade=False"

PLAY [127.0.0.1] **************************************************************
127.0.0.1: not importing file: /home/msp/error/hosts_names.yml

TASK: [debug msg="Last deployment_index = 99"] ********************************
ok: [127.0.0.1 -> 127.0.0.1] => {
    "msg": "Last deployment_index = 99"
}

TASK: [sample | Generate hosts_names in current dir] **************************
changed: [127.0.0.1 -> 127.0.0.1]

TASK: [sample | debug msg="Index = 3 0"] **************************************
ok: [127.0.0.1] => {
    "msg": "Index = 3 0"
}

PLAY RECAP ********************************************************************
127.0.0.1                  : ok=3    changed=1    unreachable=0    failed=0 

ansible-playbook sample.yml -u msp --extra-vars "userid=msp system_upgrade=False"

PLAY [127.0.0.1] **************************************************************

TASK: [debug msg="Last deployment_index = 0"] *********************************
ok: [127.0.0.1 -> 127.0.0.1] => {
    "msg": "Last deployment_index = 0"
}

TASK: [sample | Generate hosts_names in current dir] **************************
ok: [127.0.0.1 -> 127.0.0.1]

TASK: [sample | debug msg="Index = 2 0"] **************************************
ok: [127.0.0.1] => {
    "msg": "Index = 2 0"
}

PLAY RECAP ********************************************************************
127.0.0.1                  : ok=3    changed=0    unreachable=0    failed=0  

ansible-playbook sample.yml -u msp --extra-vars "userid=msp system_upgrade=True"

PLAY [127.0.0.1] **************************************************************

TASK: [debug msg="Last deployment_index = 0"] *********************************
ok: [127.0.0.1 -> 127.0.0.1] => {
    "msg": "Last deployment_index = 0"
}

TASK: [sample | Generate hosts_names in current dir] **************************
changed: [127.0.0.1 -> 127.0.0.1]

TASK: [sample | debug msg="Index = 2 0"] **************************************
ok: [127.0.0.1] => {
    "msg": "Index = 2 0"
}

PLAY RECAP ********************************************************************
127.0.0.1                  : ok=3    changed=1    unreachable=0    failed=0 

ansible-playbook sample.yml -u msp --extra-vars "userid=msp system_upgrade=True"

PLAY [127.0.0.1] **************************************************************

TASK: [debug msg="Last deployment_index = 1"] *********************************
ok: [127.0.0.1 -> 127.0.0.1] => {
    "msg": "Last deployment_index = 1"
}

TASK: [sample | Generate hosts_names in current dir] **************************
changed: [127.0.0.1 -> 127.0.0.1]

TASK: [sample | debug msg="Index = 3 1"] **************************************
ok: [127.0.0.1] => {
    "msg": "Index = 3 1"
}

PLAY RECAP ********************************************************************
127.0.0.1                  : ok=3    changed=1    unreachable=0    failed=0