The map visualizer has some issues

[unomove]

environment:
pyqtgraph==0.11.1

When ploting pose and abstract map, it raises a exception:
expected a readable buffer object

When I debug more:
"
def _drawPose(self, pose, layer=0, existing=[]):
"""Draws a pose assuming the coordinate frame matches the plot"""
items = existing
print ("here", items)
if not items:
print ("hh", pose.x, pose.y, pose.th)
items.extend([
# items.append(self._plt.plot([pose.x], [pose.y], pen=_PT_PEN))
self._plt.plot([pose.x], [pose.y],
pxMode=False,
pen=None,
symbolSize=_ROBOT_RADIUS,
symbol='o',
symbolPen=_PO_PEN,
symbolBrush=_PO_BRUSH),
# self._plt.plot([pose.x], [pose.y],
# pen=None,
# symbol=Visualiser._triangleSymbol(pose.th),
# symbolPen=_PO_PEN,
# symbolBrush=_PO_BRUSH)
])
print ("hehe", items)
else:
items[-2].setData([pose.x], [pose.y])
items[-1].setData([pose.x], [pose.y],
symbol=Visualiser._triangleSymbol(pose.th))
print ("items", items)
Visualiser._setLayer(items, layer)
return items
"

Output:
('_drawFnFromType', <class 'abstract_map_lib.visual.PosePrimitive'>)
('here', [])
('hh', -21.649642417413087, 12.420272175124676, 1.52322245842881)
expected a readable buffer object
Saving abstract map on shutdown...