On Nov 22, 2:46 pm, Florent Hivert <florent.hiv...@lri.fr> wrote: > Hi there, > > I want to report a segfault in DiGraph.automorphism_group. > > > On my machine the following code creates a segfault if > > finite_semigroup-nt.patch is applied and works if not. > > > sage: G = DiGraph() > > sage: G.add_vertices([1, 6, 9]) > > sage: G.add_edges([(9, 1, None), (9, 6, None)]) > > sage: G.automorphism_group() > > ****BBBBOOOOMMMM**** > > > Can someone confirm that the segfault happen on other machine ? > > > For Nicolas: could it be related to the recent work on categories ? > > We (Nicolas & myself) tracked back the segfault and found that it was > triggered by the category system but it should have nothing to do with it. The > problem seems to been raised by an early import of DiGraph. > > Here is a simple way to trigger the segfault: > > Starts from vanilla sage-4.7.2 together with the following patch: > > """ > # HG changeset patch > # Parent 9e29a3d84c48c399daaf3920bcb8b17273a0e876 > diff --git a/sage/categories/all.py b/sage/categories/all.py > --- a/sage/categories/all.py > +++ b/sage/categories/all.py > @@ -39,6 +39,8 @@ from finite_monoids import FiniteMonoids > from finite_groups import FiniteGroups > from finite_permutation_groups import FinitePermutationGroups > > +from sage.graphs.digraph import DiGraph > + > # fields > from number_fields import NumberFields > """ > > Then, > > sage: DiGraph().automorphism_group() > > Kaboom !!! > > I don't think I'll have time to investigate this further. Should I open a > ticket ? > > Cheers, > > Florent
Hi Florent, I tested your code with the patch and without - it worked both times: Permutation Group with generators [(1,3)] But maybe this is related, I had also problems with a crash in module digraph.py and have created a ticket here http://trac.sagemath.org/sage_trac/ticket/12054 cheers emil -- To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org
