`[@@deriving quickcheck]` causes type error

```
type 'a t = Zero | Succ of 'a t [@@deriving quickcheck]
```

causes this error:

```
This expression should not be a function, the expected type is
'a Base_quickcheck.Generator.t
```

Can you reproduce?

What is the recommended way to generate quickcheck values for this type?

Start by reproducing the reported error with the recursive type and `[@@deriving quickcheck]` snippet from the issue. Investigate how recursive types are handled by the deriving support and compare the available generation approach; done means identifying whether this is a supported bug and documenting the recommended way to generate values.

Written by the indexing model from the issue text.