NotMapped on overridden mapped base class property on EF6 throws, but has no effect on EF Core

[ajcvickers]

Model:

private abstract class AbstractBaseEntity4
{
    public long Id { get; set; }
    public abstract string AbstractBaseClassProperty { get; set; }
}

private class BaseEntity4 : AbstractBaseEntity4
{
    public string BaseClassProperty { get; set; }
    public virtual string VirtualBaseClassProperty { get; set; }
    public override string AbstractBaseClassProperty { get; set; }
}

private class Unit4 : BaseEntity4
{
    [NotMapped]
    public override string VirtualBaseClassProperty { get; set; }
    public virtual AbstractBaseEntity4 Related { get; set; }
}

Config:

modelBuilder.Entity<Unit4>();
modelBuilder.Entity<BaseEntity4>();

In EF6, this will throw. In EF Core, the NotMapped attribute is ignored and VirtualBaseClassProperty remains part of the model.

[rowanmiller]

We think this should throw