Cannot create sciline.Scope subclass instance from Scipp object returned by scipp.Variable.value

[SimonHeybrock]

import scipp as sc
import sciline as sl
from typing import TypeVar

Param = TypeVar('Param')

var = sc.scalar(sc.scalar(1.0))

class A(sl.Scope[Param, sc.Variable], sc.Variable):
    ...

A[Param](var.value)

raises TypeError: scipp._scipp.core.Variable.__init__() must be called when overriding __init__. Same problem with, e.g., sc.DataArray.

• Changing to A[Param](var.value.copy()) fixes this.
• Using other dtype such as int or float is fine.

This must be related to how we return references to scipp-objects from the value property in Scipp. I have no idea how this can interfere with what we are doing in sciline.Scope.