ansible/ansible — pull request #1469 by dhozac (2012-10-28 15:41:15+00:00)
Title: Allow vars_files sequences without a default

Currently, if you have say
```yaml
- hosts:
vars_files:
- [ "vars/packages-$ansible_pkg_mgr.yml" ]
...
```
and create a packages-yum.yml, you will get an error such as
```
ERROR: None: FATAL, no files matched for vars_files import sequence: [u'vars/packages-$ansible_pkg_mgr.yml']
```

This is from the initial vars_files import where host is None, and no facts are available. I don't think it should be enforced to have a default.