cannot save graph after adding 'object' property map
This is my first bug report, so please bear with me if I'm doing something stupid. I'm using graph-tool 2.2.17 with Python 2.7.3 on OS X.8.0.
$ python
Python 2.7.3 (default, Aug 9 2012, 13:45:17)
[GCC 4.2.1 Compatible Apple Clang 4.0 ((tags/Apple/clang-421.0.60))] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import graph_tool as gt
>>> g = gt.Graph()
>>> g.vertex_properties['vertProp'] = g.new_vertex_property('object')
>>> g.save('test.xml')
>>> g.add_vertex()
<Vertex object with index '0' at 0x10ddf3c50>
>>> g.save('test.xml')
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/graph_tool/__init__.py", line 1457, in save
self.__graph.WriteToFile(file_name, None, fmt, props)
File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/graph_tool/io.py", line 64, in pickler
pickle.dump(obj, sstream, -1)
File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/pickle.py", line 1370, in dump
Pickler(file, protocol).dump(obj)
File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/pickle.py", line 223, in dump
self.write(PROTO + chr(self.proto))
TypeError: unicode argument expected, got 'str'
>>>
Specifying g.save('test.xml', 'xml')
doesn't help.