Assertion Errors when adding a clip to a timeline with two audio tracks

Ran into this when checking the default behaviour of a timeline with two tracks of the same type.

>>> import gi
>>> from gi.repository import Gst
>>> from gi.repository import GES
>>> Gst.init (None)
[]
>>> GES.init()
True
>>> timeline = GES.Timeline.new()
>>> timeline.add_track(GES.AudioTrack.new())
True
>>> timeline.add_track(GES.AudioTrack.new())
True
>>> layer = timeline.append_layer()
>>> clip = GES.TestClip.new()
>>> layer.add_clip(clip)
__main__:1: Warning: g_atomic_ref_count_dec: assertion 'g_atomic_int_get (arc) > 0' failed

(python3:9308): GStreamer-CRITICAL **: 21:58:12.618: gst_object_unref: assertion 'object != NULL' failed

(python3:9308): GES-CRITICAL **: 21:58:12.618: ges_layer_get_auto_transition: assertion 'GES_IS_LAYER (layer)' failed

(python3:9308): GStreamer-CRITICAL **: 21:58:12.619: gst_object_unref: assertion 'object != NULL' failed

(python3:9308): GES-CRITICAL **: 21:58:12.619: ges_layer_get_auto_transition: assertion 'GES_IS_LAYER (layer)' failed

(python3:9308): GStreamer-CRITICAL **: 21:58:12.619: gst_object_unref: assertion 'object != NULL' failed

(python3:9308): GES-CRITICAL **: 21:58:12.619: ges_layer_get_auto_transition: assertion 'GES_IS_LAYER (layer)' failed
True
>>>