The test's doc string was wrong, and I fixed it in https://github.com/rspec/rspec-mocks/commit/6d47442b27624a285f47b138e6dede0f3782b786.

The old doc string was:

``` ruby
it "raises an error if 'stub_chain' follows 'any_instance'"
```

But `any_instance.stub_chain` works fine (see other specs in this file that do that).  And that's not what this test is testing.  It's testing that you can't call `stub_chain` after `and_return` (which is nonsensical).  So I updated the doc string to match what the test was actually testing.  (Unless I'm reading the test entirely wrong).