Input system doesn't appear in assembly definition assets selector on Unity 6 Preview

Unity.InputSystem does not appear in the assembly definition assets selector.

I’m using Unity 6000.0.0f1 and Input system 1.8.2. Active input handler is setted to “both”.

Given a custom assembly,
when importing “UnityEngine.InputSystem” in a script which belongs to the custom assembly namespace,
then the following error appear in the console:

 error CS0234: The type or namespace name 'InputSystem' does not exist in the namespace 'UnityEngine' (are you missing an assembly reference?)

but input system can’t be selected in the assembly definition reference asset selector.

Check the Packages “folder” in the Project view. If “Input System” doesn’t show up or is empty, you’re probably affected by this bug:

Thanks for the reply.

Yes, that was the case; the input system folder was empty. Reimporting all fix the issue.

Thanks a lot!