using System;
using System.Reflection;
using System.Runtime.InteropServices;

unsafe
{
    StructWithRefField* p = stackalloc StructWithRefField[10];

    MyClass o = new();    
    // This has GC hole. The stackallocated array of StructWithRefField is not reported to GC
    p[0].RefField = ref o.ByteField;
}

ref struct StructWithRefField
{
    public ref byte RefField;
}

class MyClass
{
    public byte ByteField;
}