Re: segfault when adding edges

[George Bissias]

Hello,

I'm new to graphviz / pygraphviz, but have some experience with python.  I'm building a medium-sized graph (257 nodes and 6769 edges).  I do this by creating the edges first, and then setting the node attributes after.  I've tried adding edges in two ways.  The first way is by iterating through the edges and adding them one-by-one using G.add_node(...).  The second way is by accumulating the edges in a list, elist, and then adding them wholesale using G.add_edges_from(elist).  In both cases python crashes with a segfault.  In the first case it's somewhere in the middle of adding the edges.

The actual edges I'm adding a very simple, just (node_label1, node_label2) without any attributes.  Originally the node labels were custom strings, but I also tried numbering the nodes and simply using repr(node_ct) as the label.  This too fails.

Does anyone in the group have a suggestion for how to solve or debug this problem?  I'm running version 2.26.0-10.el6 of graphviz, version 1.2 of pygraphviz, and CentOS 6.1.

Thanks

[Aric Hagberg]

Do the tests pass?
try
python -c "import pygraphviz; pygraphviz.test()"
If not then you have a bad installation.
Aric

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[George Bissias]

Yep good thought; tests are passing.  

I did notice something else strange though.  I was able to reproduce the failure in my script with a set of just 10 edges.  When I tried creating a graph with the same edges in a fresh python console there was no crash.  The failing script begins by loading a large pickle file.  Do you suppose that the pickle load could be causing some kind of memory corruption?

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[Aric Hagberg]

I suppose it is possible there is some issue with the pickle file.
Sounds pretty strange though.
Aric

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