System.ReadOnlySpan: Exception of type 'System.Reflection.TargetException' was thrown

[bnuzhouwei]

import System
System.ReadOnlySpan[int]((2,3,4))

got

System.Reflection.TargetException: Exception of type 'System.Reflection.TargetException' was thrown.

[slozier]

Span cannot be boxed and so it cannot be used with IronPython.