Incorrect work of [ReferencePicker] with generic inheritance

[dragon122]

Same setup as in the ReferencePicker example except we move abstract classes to a parent script:

Everything works well, but as soon as we make a generic version out of our classes-holders:

Whenever the reference picker arrow is clicked, nothing happens and a NullRef exception is thrown pointing to the line 31 in "ReferencePickerAttributeDrawer" (I guess "realType" is null).
Interestingly, if we move only one abstract class to the ParentScript - everything will work as intended.

[TylerTemp]

Hi,

Interesting, I believe this is a new feature from Unity that I didn't notice.

What's your Unity version?

When I test on 2022.3.14.f1, it shows nothing (no arrow picker at all) with a different error. The script is as you provided:

// ParentScript.cs
namespace SaintsField.Samples.Scripts.IssueAndTesting.Issue.Issue112
{
    public class ParentScript<T>: MonoBehaviour
    {
        [Serializable]
        public abstract class Base1Fruit { }

        [Serializable]
        public abstract class Base2Fruit: Base1Fruit { }
    }
}

// ChildScript.cs
namespace SaintsField.Samples.Scripts.IssueAndTesting.Issue.Issue112
{
    public class ChildScript: ParentScript<float>
    {
        [Serializable]
        public class Apple: Base2Fruit { }

        [Serializable]
        public class Orange: Base2Fruit { }

        [SerializeReference, ReferencePicker] public Base2Fruit item;
    }
}

Inspector:

Error:

The field ...ChildScript.item has the [SerializeReference] attribute applied, but is of type ....ParentScript.Base2Fruit<System.Single>, which is a generic instance type. This is not supported. You must create a non-generic subclass of your generic instance type and use that as the field type instead.

Removing ReferencePicker gives the same error, which means the error came from Unity rather than SaintsField.

So providing your unity version is appreciated.

[dragon122]

Tested on Unity 6000.0.25f1 and 6000.1.0a4 (SaintsField 3.9) with the same result.
Thanks

[TylerTemp]

Hi

This bug has been fixed in 3.9.1, please have a try.