[Nauty] possible problem with Traces?

Rastislav Kralovic kralovic at dcs.fmph.uniba.sk
Thu Jun 7 03:46:59 AEST 2018


Hello all,

I experienced a weird behavior of the Traces. I installed from the 
archive auty26r10.tar.gz, compiled, runalltests claims all test have 
passed.

I have a graph (see below) in a file aaa.dre. Running dreadnaught 
session "At <aaa.dre x" segfaults like this

Dreadnaut version 2.6 (64 bits).
 > At <aaa.dre x
  Level 1:  16 cells; 4 singletons; target cell: 36; 36 orbits; 20 nodes 
(2 kept); 2 updates;
Segmentation fault

The sparse version "As <aaa.dre x" works as expected:

Dreadnaut version 2.6 (64 bits).
 > As <aaa.dre x
(13 31)(14 32)
level 3:  34 orbits; 14 fixed; index 2
(6 24)(7 25)
level 2:  32 orbits; 7 fixed; index 2
(0 2)(3 17)(4 16)(5 15)(6 14)(7 13)(8 12)(9 11)(18 20)(21 35)(22 34)(23 33)
    (24 32)(25 31)(26 30)(27 29)
(0 18)(1 19)(2 20)(3 21)(4 22)(5 23)(8 26)(9 27)(10 28)(11 29)(12 30)(15 33)
    (16 34)(17 35)
level 1:  1 cell; 10 orbits; 0 fixed; index 4/36
10 orbits; grpsize=16; 4 gens; 22 nodes (9 bad leaves); maxlev=4
cpu time = 0.00 seconds

I am actually using the C interface, so for now I just switched to 
calling sparsenauty instead of Traces, but I wonder if you can reproduce 
the segfault. Am I doing something wrong (like, am I missing something 
that Traces need to be called properly)?

Best,

Rasto


PS. contents of the aaa.dre file:


n=36 $=0 g
   0 :  1 17 27;
   1 :  0 2 28;
   2 :  1 3 29;
   3 :  2 4 34;
   4 :  3 5 35;
   5 :  4 6 24;
   6 :  5 7 23;
   7 :  6 8 26;
   8 :  7 9 25;
   9 :  8 10 18;
  10 :  9 11 19;
  11 :  10 12 20;
  12 :  11 13 31;
  13 :  12 14 30;
  14 :  13 15 33;
  15 :  14 16 32;
  16 :  15 17 21;
  17 :  0 16 22;
  18 :  9 19 35;
  19 :  10 18 20;
  20 :  11 19 21;
  21 :  16 20 22;
  22 :  17 21 23;
  23 :  6 22 24;
  24 :  5 23 25;
  25 :  8 24 26;
  26 :  7 25 27;
  27 :  0 26 28;
  28 :  1 27 29;
  29 :  2 28 30;
  30 :  13 29 31;
  31 :  12 30 32;
  32 :  15 31 33;
  33 :  14 32 34;
  34 :  3 33 35;
  35 :  4 18 34;
$$



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