Prior to the current version, I was able to do this:

has_one :author, inverse_of: nil, class_name: "User"

And it worked fine. This was to do a one-sided has_one (ie, a one -> many relationship).

Now, when doing the rspec test I get this error from the factory after I define the author:

undefined method `show_id=' for #<User:0x007ffcaf719f40>