Clean up subinterpreters only after modules (incl. __main__) have been cleaned up.

Author: ericsnowcurrently

Python/pylifecycle.c

@@ -1999,7 +1999,6 @@ _Py_Finalize(_PyRuntimeState *runtime)
     _PyAtExit_Call(tstate->interp);
 
     assert(_PyThreadState_GET() == tstate);
-    finalize_subinterpreters();
 
     /* Copy the core config, PyInterpreterState_Delete() free
        the core config memory */
@@ -2081,6 +2080,9 @@ _Py_Finalize(_PyRuntimeState *runtime)
     _PyImport_FiniExternal(tstate->interp);
     finalize_modules(tstate);
 
+    /* Clean up any lingering subinterpreters. */
+    finalize_subinterpreters();
+
     /* Print debug stats if any */
     _PyEval_Fini();