"hosts: all" not supported

[rndmh3ro]

The host all is currently not supported:

- name: foo
  hosts: all
  user: root
  gather_facts: True
  roles:
  - foo

[root@server ansible]# rake -T --trace
rake aborted!
NoMethodError: undefined method `each' for "all":String
/etc/ansible/Rakefile:12:in `block (2 levels) in <top (required)>'
/etc/ansible/Rakefile:11:in `each'
/etc/ansible/Rakefile:11:in `block in <top (required)>'
/opt/rh/rh-ruby22/root/usr/share/gems/gems/rake-10.4.2/lib/rake/task_manager.rb:209:in `in_namespace'
/opt/rh/rh-ruby22/root/usr/share/gems/gems/rake-10.4.2/lib/rake/dsl_definition.rb:147:in `namespace'
/etc/ansible/Rakefile:10:in `<top (required)>'
/opt/rh/rh-ruby22/root/usr/share/gems/gems/rake-10.4.2/lib/rake/rake_module.rb:28:in `load'
/opt/rh/rh-ruby22/root/usr/share/gems/gems/rake-10.4.2/lib/rake/rake_module.rb:28:in `load_rakefile'
/opt/rh/rh-ruby22/root/usr/share/gems/gems/rake-10.4.2/lib/rake/application.rb:689:in `raw_load_rakefile'
/opt/rh/rh-ruby22/root/usr/share/gems/gems/rake-10.4.2/lib/rake/application.rb:94:in `block in load_rakefile'
/opt/rh/rh-ruby22/root/usr/share/gems/gems/rake-10.4.2/lib/rake/application.rb:176:in `standard_exception_handling'
/opt/rh/rh-ruby22/root/usr/share/gems/gems/rake-10.4.2/lib/rake/application.rb:93:in `load_rakefile'
/opt/rh/rh-ruby22/root/usr/share/gems/gems/rake-10.4.2/lib/rake/application.rb:77:in `block in run'
/opt/rh/rh-ruby22/root/usr/share/gems/gems/rake-10.4.2/lib/rake/application.rb:176:in `standard_exception_handling'
/opt/rh/rh-ruby22/root/usr/share/gems/gems/rake-10.4.2/lib/rake/application.rb:75:in `run'
/opt/rh/rh-ruby22/root/usr/bin/rake:33:in `<main>'