[root@RS1 ~]# salt -G 'roles:nginx' test.ping
[WARNING ] Key grains with value roles:nginx env:prod has an invalid type of <type 'str'>, a dict is required for this value
[WARNING ] Key grains with value roles:nginx env:prod has an invalid type of <type 'str'>, a dict is required for this value
[WARNING ] Key grains with value roles:nginx env:prod has an invalid type of <type 'str'>, a dict is required for this value
[WARNING ] Key grains with value roles:nginx env:prod has an invalid type of <type 'str'>, a dict is required for this value