[GNC-dev] Python bindings: "invalid unclassed pointer in cast to 'QofInstance'"

I get the following errors/warnings when using ApplyPayment to a
customer.

* 06:56:27  WARN <GLib-GObject> invalid unclassed pointer in cast to 'QofInstance'
* 06:56:27 ERROR <gnc.engine> QofBook* qof_instance_get_book(gconstpointer): assertion 'QOF_IS_INSTANCE(inst)' failed
* 06:56:27  WARN <GLib-GObject> invalid unclassed pointer in cast to 'QofInstance'
* 06:56:27 ERROR <gnc.engine> void qof_instance_get(const QofInstance*, const gchar*, ...): assertion 'QOF_IS_INSTANCE (inst)' failed

The same error is produced by the Python example
simple_business_create.py.

The resulting account entries appear correct as well as the balance
sheet and income reports.

I'm running yesterday's stable head 369b0855f on Ubuntu 22.04.2.

Steve