Issue with specifying overrides of generic bases

[hamarb123]

If I have some code like

using System;
public class C<T> : i<T> {
    public void M() {
    }
    T i<T>.a() =>default;
}
public interface i<T> {T a();}

It complies in a .override instruction

.override method instance !0 class i`1<!T>::a()

I don't know if my code is wrong, but when I try to Import a reference like this to use as a .override instruction, I get this error:

System.NullReferenceException: 'Object reference not set to an instance of an object.'

stack was null.

reference.ToString():

TValue System.Collections.Generic.IDictionary`2<!0,!1>::get_Item(TKey)

Any ideas?

[hamarb123]

The context is that I wanted the all the bases of a method, so I used https://github.com/mono/linker/blob/main/src/linker/Linker/TypeMapInfo.cs
I changed some parts of the code so that it would instantiate the generic methods to be able to use them in the .override instruction, by using the following code:

static MethodReference EnsureGenericReference(MethodDefinition def, TypeReference type)
{
	if (type is GenericInstanceType t)
	{
		var method = TypeReferenceExtensions.MakeMethodReferenceForGenericInstanceType(t, def);
		return method;
	}
	return def;
}

This code fails when attempting to import the method that was created