Undefined method error in Ruby on rails. However the method doesn't exist at all

I'm getting the following error:

undefined method `posix_group' for ["494149846749", "12"]:Array. 

However I don't have a method named possix_group in my entire code package. But I do have a piece of code

posix_group = application.posix_group

Also some annotations like @possix_group. I can't find a method named with the above to solve the problem.