Random Access Violations on shutdown #1977

Environment

• Pythonnet version: 3.0.0.post1
• Python version: 3.8.10
• Operating System: Windows 11
• .NET Runtime: .NET Framework 472

Details

• Describe what you were trying to get done.

  I am getting random access violations during shutdown in pythonnet. The issue can be re-produced with a C# function as simple as

public static int Add(int a, int b) => a + b;

I get the access violation; however, it is not deterministic at all. Some times, it succeeds as expected, other times I get this. Note that I am upgrading from pythonnet 2.5.2 to pythonnet 3.0.0.post1 so this code used to work. All I am doing is invoking this code from python. I am running this python code that uses pythonnet in pytest. I haven't seen this when we were using pythonnet 2.5.2.

• If there was a crash, please include the traceback here.

Unhandled Exception: System.AccessViolationException: Attempted to read or write protected memory. This is often an indication that other memory is corrupt.
   at Python.Runtime.Runtime.PyObject_TYPE(BorrowedReference op)
   at Python.Runtime.Runtime.NullGCHandles(IEnumerable`1 objects)
   at Python.Runtime.Runtime.TryCollectingGarbage(Int32 runs, Boolean forceBreakLoops)
   at Python.Runtime.Runtime.Shutdown()
   at Python.Runtime.PythonEngine.Shutdown()
   at Python.Runtime.Loader.Shutdown(IntPtr data, Int32 size)