Ansible 2.0 nested task loops don't work

actual.txt

> ansible-playbook main.yml -i hosts -c local

PLAY ***************************************************************************

TASK [setup] *******************************************************************
ok: [localhost]

TASK [debug] *******************************************************************
ok: [localhost] => {
    "deploy_descriptors": [
        {
            "artifact1_version": "1.0", 
            "artifact2_version": "1.1", 
            "name": "foo"
        }, 
        {
            "artifact1_version": "1.0", 
            "artifact2_version": "1.0", 
            "name": "bar"
        }
    ]
}

TASK [main: deploy the sites in deploy_descriptors] ****************************
included: /Users/gregsymons/projects/personal/ansible2_nested_loops/deploy_one_site.yml for localhost
included: /Users/gregsymons/projects/personal/ansible2_nested_loops/deploy_one_site.yml for localhost

TASK [set_fact] ****************************************************************
ok: [localhost]

TASK [deploy_one_site: deploy the artifacts for foo] ***************************
included: /Users/gregsymons/projects/personal/ansible2_nested_loops/deploy_artifact.yml for localhost
included: /Users/gregsymons/projects/personal/ansible2_nested_loops/deploy_artifact.yml for localhost
included: /Users/gregsymons/projects/personal/ansible2_nested_loops/deploy_artifact.yml for localhost
included: /Users/gregsymons/projects/personal/ansible2_nested_loops/deploy_artifact.yml for localhost

TASK [set_fact] ****************************************************************
ok: [localhost]

TASK [deploy_artifact: inspect the variables in this context (foo] *************
ok: [localhost] => {
    "msg": "deployment={u'artifact1_version': u'1.0', u'artifact2_version': u'1.1', u'name': u'foo'} deployment_id=0 artifact_base_url=0 artifact_version={u'artifact1_version': u'1.0', u'artifact2_version': u'1.1', u'name': u'foo'}"
}

TASK [set_fact] ****************************************************************
ok: [localhost]

TASK [deploy_artifact: inspect the variables in this context (foo] *************
ok: [localhost] => {
    "msg": "deployment={u'artifact1_version': u'1.0', u'artifact2_version': u'1.1', u'name': u'foo'} deployment_id=0 artifact_base_url=0 artifact_version={u'artifact1_version': u'1.0', u'artifact2_version': u'1.1', u'name': u'foo'}"
}

TASK [set_fact] ****************************************************************
ok: [localhost]

TASK [deploy_artifact: inspect the variables in this context (foo] *************
ok: [localhost] => {
    "msg": "deployment={u'artifact1_version': u'1.0', u'artifact2_version': u'1.1', u'name': u'foo'} deployment_id=0 artifact_base_url=0 artifact_version={u'artifact1_version': u'1.0', u'artifact2_version': u'1.1', u'name': u'foo'}"
}

TASK [set_fact] ****************************************************************
ok: [localhost]

TASK [deploy_artifact: inspect the variables in this context (foo] *************
ok: [localhost] => {
    "msg": "deployment={u'artifact1_version': u'1.0', u'artifact2_version': u'1.1', u'name': u'foo'} deployment_id=0 artifact_base_url=0 artifact_version={u'artifact1_version': u'1.0', u'artifact2_version': u'1.1', u'name': u'foo'}"
}

TASK [set_fact] ****************************************************************
ok: [localhost]

TASK [deploy_one_site: deploy the artifacts for bar] ***************************
included: /Users/gregsymons/projects/personal/ansible2_nested_loops/deploy_artifact.yml for localhost
included: /Users/gregsymons/projects/personal/ansible2_nested_loops/deploy_artifact.yml for localhost
included: /Users/gregsymons/projects/personal/ansible2_nested_loops/deploy_artifact.yml for localhost

TASK [set_fact] ****************************************************************
ok: [localhost]

TASK [deploy_artifact: inspect the variables in this context (bar] *************
ok: [localhost] => {
    "msg": "deployment={u'artifact1_version': u'1.0', u'artifact2_version': u'1.0', u'name': u'bar'} deployment_id=1 artifact_base_url=1 artifact_version={u'artifact1_version': u'1.0', u'artifact2_version': u'1.0', u'name': u'bar'}"
}

TASK [set_fact] ****************************************************************
ok: [localhost]

TASK [deploy_artifact: inspect the variables in this context (bar] *************
ok: [localhost] => {
    "msg": "deployment={u'artifact1_version': u'1.0', u'artifact2_version': u'1.0', u'name': u'bar'} deployment_id=1 artifact_base_url=1 artifact_version={u'artifact1_version': u'1.0', u'artifact2_version': u'1.0', u'name': u'bar'}"
}

TASK [set_fact] ****************************************************************
ok: [localhost]

TASK [deploy_artifact: inspect the variables in this context (bar] *************
ok: [localhost] => {
    "msg": "deployment={u'artifact1_version': u'1.0', u'artifact2_version': u'1.0', u'name': u'bar'} deployment_id=1 artifact_base_url=1 artifact_version={u'artifact1_version': u'1.0', u'artifact2_version': u'1.0', u'name': u'bar'}"
}

PLAY RECAP *********************************************************************
localhost                  : ok=27   changed=0    unreachable=0    failed=0   

>

deploy_artifact.yml

- set_fact: artifact_base_url='{{item.0}}' artifact_version='{{item.1}}'
- name: 'deploy_artifact: inspect the variables in this context ({{ deployment.name }}'
  debug: msg='deployment={{deployment}} deployment_id={{deployment_id}} artifact_base_url={{artifact_base_url}} artifact_version={{artifact_version}}'

deploy_one_site.yml

- set_fact: deployment_id={{ item.0 }} deployment={{ item.1 }}

- name: 'deploy_one_site: deploy the artifacts for {{ deployment.name }}'
  include: 'deploy_artifact.yml'
  with_items:
    - [ '{{ artifact1_base_url }}', '{{ deployment.artifact1_version }}' ]
    - [ '{{ artifact2_base_url }}', '{{ deployment.artifact2_version }}' ]

expected.txt

> ansible-playbook main.yml -i hosts -c local

PLAY ***************************************************************************

TASK [setup] *******************************************************************
ok: [localhost]

TASK [debug] *******************************************************************
ok: [localhost] => {
    "deploy_descriptors": [
        {
            "artifact1_version": "1.0", 
            "artifact2_version": "1.1", 
            "name": "foo"
        }, 
        {
            "artifact1_version": "1.0", 
            "artifact2_version": "1.0", 
            "name": "bar"
        }
    ]
}

TASK [main: deploy the sites in deploy_descriptors] ****************************
included: /Users/gregsymons/projects/personal/ansible2_nested_loops/deploy_one_site.yml for localhost
included: /Users/gregsymons/projects/personal/ansible2_nested_loops/deploy_one_site.yml for localhost

TASK [set_fact] ****************************************************************
ok: [localhost]

TASK [deploy_one_site: deploy the artifacts for foo] ***************************
included: /Users/gregsymons/projects/personal/ansible2_nested_loops/deploy_artifact.yml for localhost
included: /Users/gregsymons/projects/personal/ansible2_nested_loops/deploy_artifact.yml for localhost

TASK [set_fact] ****************************************************************
ok: [localhost]

TASK [deploy_artifact: inspect the variables in this context (foo] *************
ok: [localhost] => {
    "msg": "deployment={u'artifact1_version': u'1.0', u'artifact2_version': u'1.1', u'name': u'foo'} deployment_id=0 artifact_base_url=https://artifacts.example.com/repo/artifact1 artifact_version=1.0"
}

TASK [set_fact] ****************************************************************
ok: [localhost]

TASK [deploy_artifact: inspect the variables in this context (foo] *************
ok: [localhost] => {
    "msg": "deployment={u'artifact1_version': u'1.0', u'artifact2_version': u'1.1', u'name': u'foo'} deployment_id=0 artifact_base_url=https://artifacts.example.com/repo/artifact2 artifact_version=1.1"
}


TASK [set_fact] ****************************************************************
ok: [localhost]

TASK [deploy_one_site: deploy the artifacts for bar] ***************************
included: /Users/gregsymons/projects/personal/ansible2_nested_loops/deploy_artifact.yml for localhost
included: /Users/gregsymons/projects/personal/ansible2_nested_loops/deploy_artifact.yml for localhost

TASK [set_fact] ****************************************************************
ok: [localhost]

TASK [deploy_artifact: inspect the variables in this context (foo] *************
ok: [localhost] => {
    "msg": "deployment={u'artifact1_version': u'1.0', u'artifact2_version': u'1.0', u'name': u'bar'} deployment_id=1 artifact_base_url=https://artifacts.example.com/repo/artifact1 artifact_version=1.0"
}

TASK [set_fact] ****************************************************************
ok: [localhost]

TASK [deploy_artifact: inspect the variables in this context (foo] *************
ok: [localhost] => {
    "msg": "deployment={u'artifact1_version': u'1.0', u'artifact2_version': u'1.1', u'name': u'foo'} deployment_id=1 artifact_base_url="https://artifacts.example.com/repo/artifact2" artifact_version=1.0"
}

PLAY RECAP *********************************************************************
localhost                  : ok=27   changed=0    unreachable=0    failed=0   

>

hosts

[localhost]
localhost

[localhost:vars]

main.yml

---
- hosts: localhost
  vars:
    deploy_descriptors:
      - name: 'foo'
        artifact1_version: '1.0'
        artifact2_version: '1.1'
      - name: 'bar'
        artifact1_version: '1.0'
        artifact2_version: '1.0'

    artifact1_base_url: 'https://artifacts.example.com/repo/artifact1'
    artifact2_base_url: 'https://artifacts.example.com/repo/artifact2'
  tasks:
    - debug: var='deploy_descriptors'
    - name: 'main: deploy the sites in deploy_descriptors'
      include: 'deploy_one_site.yml'
      with_indexed_items: '{{ deploy_descriptors }}'