gt.subgraph_isomorphism - No static implementation was found for the desired routine

Traceback (most recent call last):
  File "./bug_gtisomorphism2.py", line 13, in <module>
    vmaps, emaps = gt.subgraph_isomorphism(G,G,max_n=1,vertex_label=(G.vp['label'],G.vp['label']),edge_label=(G.ep['label'],G.ep['label']))
  File "[..]graph_tool/topology/__init__.py", line 305, in subgraph_isomorphism
    vertex_label = perfect_prop_hash(vertex_label, htype="int32_t")
  File "[..]graph_tool/decorators.pyc", line 2, in perfect_prop_hash
    q��Sc
  File "[..]graph_tool/decorators.py", line 104, in wrap
    return func(*args, **kwargs)
  File "[..]graph_tool/__init__.py", line 1053, in perfect_prop_hash
    _prop('v', g, hvprop), hdict)
RuntimeError: No static implementation was found for the desired routine. This is a graph_tool bug. :-( Please follow but report instructions at http://graph-tool.skewed.de/tickets. What follows is debug information.

GrapQ��8�?��8�?dAdaptor<boost::adj_list<unsigned long> >*

Action: std::_Bind_result<void, do_perfect_vhash (std::_Placeholder<1>, std::_Placeholder<2>, std::_Placeholder<3>, std::reference_wrapper<boost::any>)>

Arg 1: boost::checked_vector_property_map<std::string, boost::typed_identity_property_map<unsigned long> >

Arg 2: boost::checked_vector_property_map<int, boost::typed_identity_property_map<unsigned long> >

import graph_tool.all as gt

G = gt.complete_graph(10)

G.vp['label'] = vlbl = G.new_vertex_property("string")
for v in G.vertices(): vlbl[v] = "temp"
G.ep['label'] = elbl = G.new_edge_property("string")
for e in G.edges(): elbl[e] = "test"

vmaps, emaps = gt.subgraph_isomorphism(G,G,max_n=1,vertex_label=(G.vp['label'],G.vp['label']),edge_label=(G.ep['label'],G.ep['label']))

I am not sure why I see the wrong characters in GrapQ��8�?��8�?dAdaptor.