Dear Tiago, Thank you for your great work on this very useful library! I have played with it for a project over the last few days, and today I have discovered a real roadblock: subgraph_isomorphism seems to segfault (at least very often, have not found any pattern yet) when searching on a graph with filtered vertices (or the equivalent GraphView) --- this has never occurred to me for an unfiltered graph. Here is a minimal example: ##### from graph_tool.all import * G = price_network(100) sub = Graph() sub.add_vertex(3) sub.add_edge(sub.vertex(0), sub.vertex(1)) sub.add_edge(sub.vertex(1), sub.vertex(2)) # WORKS FINE: print G print subgraph_isomorphism(sub, G, random=False) # FILTER FOR "OLDEST" VERTICES vmap = G.new_vertex_property("bool") for i in range(20): vmap[G.vertex(i)] = True # EITHER THIS... G.set_vertex_filter(vmap) print G print subgraph_isomorphism(sub, G, random=False) # segmentation fault! G.set_vertex_filter(None) # OR THIS... H = GraphView(G, vfilt=vmap) print H print subgraph_isomorphism(sub, H, random=False) # segmentation fault! ##### I am using the latest release from the oneiric repo, here is the show_config() output: ##### version: 2.2.15 (commit b435362a, Wed Aug 31 23:11:56 2011 +0200) gcc version: 4.6.1 compilation flags: -I/usr/include/python2.7 -I/usr/include -I/usr/lib/pymodules/python2.7/nu mpy/core/include/numpy -I/usr/lib/python2.7/dist-packages/scipy -g -O2 -g -O2 -Wall -Wall -ft emplate-depth-150 -Wno-deprecated -Wno-unknown-pragmas -O99 -fvisibility=default -fvisibility -inlines-hidden -fopenmp -Wl,-Bsymbolic-functions -L/usr/lib/python2.7 -lpython2.7 install prefix: /usr python dir: /usr/lib/python2.7/dist-packages graph filtering: True openmp: True uname: Linux acer 3.0.0-17-generic #30-Ubuntu SMP Thu Mar 8 20:45:39 UTC 2012 x86_64 ##### Any help/ideas on this would be greatly appreciated! Please let me know whether/how I can provide any more information or test results to resolve this issue. Kind regards, Ingo