gistfile1.txt

developers_groups:
 - 'developres'
 - 'ninjas'

ops_groups:
 - 'ops'
 - 'wheel'

robots_groups:
 - 'robots'

company_groups:
 - 'company'

all_groups: developers_groups + ops_groups + robots_groups + company_groups

....

  tasks:
    - name: create or modify enabled user groups
      group: name={{ item }} state=present
      with_items: all_groups
      
....

TASK: [create or modify enabled user groups] **********************************
failed: [centos6vm] => (item=developers_groups + ops_groups + robots_groups + company_groups) => {"failed": true, "item": "developers_groups + ops_groups + robots_groups + company_groups"}
msg: this module requires key=value arguments (['name=developers_groups', '+', 'ops_groups', '+', 'robots_groups', '+', 'company_groups', 'state=present'])

FATAL: all hosts have already failed -- aborting