Re-opening and setting the stage as 'needs patch': at least the cross-compilation should fail with a clear message when the cross-built libraries names and those of the native interpreter have the same suffix.

> Assuming that you can rely on the loader to not open target binaries when they're on the path to load from is unwise.

Meanwhile a workaround may be to build the native interpreter with Py_DEBUG defined (using the --with-pydebug configure option) so that libraries names become different.