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##### SUMMARY
<!--- Explain the problem briefly below -->
I set cache settings in inventory and inventory plugin script ini section according to the docs, but cache isn't created. I tried with jsonfile cache plugin. 
Docs:
[https://docs.ansible.com/ansible/latest/plugins/cache.html#enabling-inventory-cache-plugins](https://docs.ansible.com/ansible/latest/plugins/cache.html#enabling-inventory-cache-plugins)
[https://docs.ansible.com/ansible/latest/plugins/inventory/script.html](https://docs.ansible.com/ansible/latest/plugins/inventory/script.html)
##### ISSUE TYPE
- Bug Report

##### COMPONENT NAME
<!--- Write the short name of the module, plugin, task or feature below, use your best guess if unsure -->
<!--- !component =lib/ansible/plugins/inventory/script.py-->
inventory plugin script
##### ANSIBLE VERSION
<!--- Paste verbatim output from "ansible --version" between quotes -->
```paste below
ansible 2.8.6
  config file = /etc/ansible/ansible.cfg
  configured module search path = ['/home/vagrant/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /home/vagrant/.local/lib/python3.5/site-packages/ansible
  executable location = /home/vagrant/.local/bin/ansible
  python version = 3.5.2 (default, Oct  8 2019, 13:06:37) [GCC 5.4.0 20160609]
```

##### CONFIGURATION
<!--- Paste verbatim output from "ansible-config dump --only-changed" between quotes -->
```paste below
CACHE_PLUGIN(/etc/ansible/ansible.cfg) = jsonfile
CACHE_PLUGIN_CONNECTION(/etc/ansible/ansible.cfg) = /tmp
INVENTORY_CACHE_ENABLED(/etc/ansible/ansible.cfg) = True
INVENTORY_CACHE_PLUGIN(/etc/ansible/ansible.cfg) = jsonfile
INVENTORY_CACHE_PLUGIN_CONNECTION(/etc/ansible/ansible.cfg) = /tmp
INVENTORY_CACHE_TIMEOUT(/etc/ansible/ansible.cfg) = 600
INVENTORY_PLUGIN_SCRIPT_CACHE(/etc/ansible/ansible.cfg) = True
```

##### OS / ENVIRONMENT
<!--- Provide all relevant information below, e.g. target OS versions, network device firmware, etc. --
Ubuntu 16.04
>


##### STEPS TO REPRODUCE
<!--- Describe exactly how to reproduce the problem, using a minimal test-case -->
1. Set configuration file for inventory cache with jsonfile plugin
2. Run playbook with invetory script plugin source

<!--- HINT: You can paste gist.github.com links for larger files -->

##### EXPECTED RESULTS
<!--- Describe what you expected to happen when running the steps above -->
JSON inventory file in /tmp folder

##### ACTUAL RESULTS
<!--- Describe what actually happened. If possible run with extra verbosity (-vvvv) -->
JSON inventory file isn't created


from __future__ import (absolute_import, division, print_function)
__metaclass__ = type
DOCUMENTATION = '''
    inventory: script
    version_added: "2.4"
    short_description: Executes an inventory script that returns JSON
    options:
      cache:
        description: Toggle the usage of the configured Cache plugin.
        default: False
        type: boolean
        ini:
           - section: inventory_plugin_script