Hello, Since past couple days I encounter a new RuntimeError that I fail to explain. See below the end of the error stack : File "utils/graph.py", line 345, in multiple_shortest_path p = graph.vertex(pred_map[v]) File "/usr/lib/python2.7/dist-packages/graph_tool/__init__.py", line 1777, in vertex v = libcore.get_vertex(self.__graph, int(i), use_index) RuntimeError: Edge filter is active but vertex filter is not. This is a bug. This error is raised in a customized version of the *graph_tool.topology.shortest_path *function. This function (named multiple_shortest_path) is "optimized" to compute multiple shortest paths from a source vertex to a set of targets. This function is presented below. Would anybody have some hints on the reason of this intermittent error ? Thanks, F. def multiple_shortest_path(graph, source, targets, distances, pred_map): """ :param graph: a GraphTool.Graph instance. :param source: origin vertex id in *graph* :param targets: the vertices ids (in *graph*) for which we compute the shortest paths :param distances: a property map that contains distances from source vertex to each vertex :param* pred_map: a property map of predecessor computed by graph_tool.shortest_distance* """ # sort the targets from the farthest to the closest targets, _ = zip(*sorted([(graph.vertex(t), distances.a[t]) for t in targets], key=lambda x: x[1])) vlists = {} for tgt in targets: if pred_map[tgt] == int(tgt) and tgt != source: # Ain't no path to target (should not happen, but better safe than sorry) vlists[tgt] = [] v = tgt vlist = [tgt] # we crawl back the predecessor map until the source is reached while v != source: # one step more toward the source p = graph.vertex(pred_map[v]) if p in vlists: # we already know the shortest_path (avoid useless crawl back to the source) vlist = vlists[p] + vlist v = graph.vertex(vlist[0]) else: # saves the current step vlist.insert(0, p) # predecessor vertex becomes the current vertex (recall we crawl back from target until source) v = p # Saves the vertices list from target to source (ie. the shortest path wrt. the predecessor map) vlists[tgt] = vlist return vlists