Hello, 

I am using Debian and I have two versions of graph-tool available. I have a program we would like to distribute using graph-tool but it turns out that it runs fine with version graph-tool_2.2.19-1 but it does not with version 2.2.23-1. 

 File "process.py", line 168, in <module>
    main()
  File "process.py", line 126, in main
    processor.process_text((input_text, parse_tree))
  File "process.py", line 100, in process_text
    self.reset_graph()
  File "process.py", line 37, in reset_graph
    self.graph = self.graph_builder.new_graph()
  File "/home/ragerri/pythoncode/corefgraph-en-opener/corefgraph/graph/graph_builder.py", line 92, in new_graph
    GraphWrapper.set_properties(graph=graph, graph_properties={'graph_builder': self})
  File "/home/ragerri/pythoncode/corefgraph-en-opener/corefgraph/graph/utils.py", line 82, in set_properties
    graph.graph_properties[name][graph] = property_value
TypeError: 'NoneType' object does not support item assignment

This error does not arise if I remove [graph]. 

However, i would like to know, if possible, when the library changed this behaviour so I could tell users of my system to install from a particular version of graph-tool to other. 

Thanks! 

Rodrigo