[Cbc-tickets] [COIN-OR Branch-and-Cut MIP Solver] #70: Cbc, reproducible segmentation fault

[COIN-OR Branch-and-Cut MIP Solver]

#70: Cbc, reproducible segmentation fault
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 Reporter:  nowozin     |       Owner:  somebody
     Type:  defect      |      Status:  new     
 Priority:  major       |   Milestone:          
Component:  component1  |     Version:          
 Keywords:              |  
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 A MILP problem discussed at
 http://forums.ilog.com/optimization/index.php/topic,1045.0.html
 consistently crashes Cbc as follows:

 {{{
 $ /opt/coin-cbc-trunk20090317/bin/cbc sol21.lp
 Coin Cbc and Clp Solver version 1.2trunk, build Mar 17 2009
 command line - /opt/coin-cbc-trunk20090317/bin/cbc sol21.lp (default
 strategy 1)
 Continuous objective value is 2.95918 - 0.06 seconds
 Cgl0003I 0 fixed, 1 tightened bounds, 0 strengthened rows, 0 substitutions
 Cgl0004I processed model has 179 rows, 1422 columns (1422 integer) and
 7588 elements
 Objective coefficients multiple of 1
 Cutoff increment increased from 1e-05 to 0.999
 Cbc0045I 1 integer variables out of 1422 objects (1422 integer) have cost
 of 1 - high priority
 Cbc0045I branch on satisfied Y create fake objective Y random cost N
 Cbc0038I Pass   1: suminf.   10.20918 (54) obj. 13 iterations 374
 Cbc0038I Pass   2: suminf.    3.57143 (31) obj. 27 iterations 206
 Cbc0038I Pass   3: suminf.    4.40476 (31) obj. 27 iterations 27
 Cbc0038I Pass   4: suminf.    4.19048 (30) obj. 27 iterations 87
 Cbc0038I Pass   5: suminf.    4.14286 (30) obj. 27 iterations 7
 Cbc0038I Pass   6: suminf.    4.09524 (31) obj. 27 iterations 47
 Cbc0038I Pass   7: suminf.    4.45238 (32) obj. 47.8333 iterations 33
 Cbc0038I Pass   8: suminf.    4.35714 (33) obj. 47.8333 iterations 146
 Cbc0038I Pass   9: suminf.    4.30952 (32) obj. 56.8333 iterations 8
 Cbc0038I Pass  10: suminf.    4.30952 (32) obj. 56.8333 iterations 77
 Cbc0038I Pass  11: suminf.    4.64286 (32) obj. 58.5 iterations 15
 Cbc0038I Pass  12: suminf.    4.64286 (32) obj. 58.5 iterations 89
 Cbc0038I Pass  13: suminf.    4.30952 (32) obj. 56.8333 iterations 8
 Cbc0038I Pass  14: suminf.    9.65967 (52) obj. 100001 iterations 206
 Cbc0038I Pass  15: suminf.    3.32857 (26) obj. 100116 iterations 122
 Cbc0038I Pass  16: suminf.    2.92857 (25) obj. 100117 iterations 139
 Cbc0038I Pass  17: suminf.    4.69048 (20) obj. 100083 iterations 85
 Cbc0038I Pass  18: suminf.    4.19048 (21) obj. 100083 iterations 44
 Cbc0038I Pass  19: suminf.    4.40476 (23) obj. 100104 iterations 52
 Cbc0038I Pass  20: suminf.    4.40476 (23) obj. 100104 iterations 28
 Cbc0038I Pass  21: suminf.    4.07143 (24) obj. 100102 iterations 6
 Cbc0038I Pass  22: suminf.    3.40476 (23) obj. 100103 iterations 47
 Cbc0038I Pass  23: suminf.    5.26190 (22) obj. 100127 iterations 36
 Cbc0038I Pass  24: suminf.    4.83333 (23) obj. 100127 iterations 66
 Cbc0038I Pass  25: suminf.    3.26190 (23) obj. 100103 iterations 44
 Cbc0038I Pass  26: suminf.    3.19048 (23) obj. 100103 iterations 139
 Cbc0038I Pass  27: suminf.    5.42857 (22) obj. 100127 iterations 70
 Cbc0038I Pass  28: suminf.    5.14202 (30) obj. 100048 iterations 300
 Cbc0038I Pass  29: suminf.    3.38095 (26) obj. 100048 iterations 99
 Cbc0038I Pass  30: suminf.    2.71429 (24) obj. 100048 iterations 119
 Cbc0038I No solution found this major pass
 Cbc0038I Before mini branch and bound, 1172 integers at bound fixed and 0
 continuous
 Cbc0038I Full problem 179 rows 1422 columns, reduced to 179 rows 249
 columns - too large
 Cbc0038I Mini branch and bound did not improve solution (0.33 seconds)
 Cbc0038I After 0.33 seconds - Feasibility pump exiting - took 0.33 seconds
 Cbc0031I 616 added rows had average density of 11.0763
 Cbc0013I At root node, 616 cuts changed objective from 2.95918 to 5.53236
 in 57 passes
 Cbc0014I Cut generator 0 (Probing) - 1629 row cuts, 0 column cuts (616
 active)  in 1.512 seconds - new frequency is 1
 Cbc0014I Cut generator 1 (Gomory) - 116 row cuts, 0 column cuts (0 active)
 in 6.084 seconds - new frequency is -100
 Cbc0014I Cut generator 2 (Knapsack) - 1761 row cuts, 0 column cuts (0
 active)  in 0.204 seconds - new frequency is 1
 Cbc0014I Cut generator 3 (Clique) - 0 row cuts, 0 column cuts (0 active)
 in 0.224 seconds - new frequency is -100
 Cbc0014I Cut generator 4 (MixedIntegerRounding2) - 151 row cuts, 0 column
 cuts (0 active)  in 0.156 seconds - new frequency is -100
 Cbc0014I Cut generator 5 (FlowCover) - 0 row cuts, 0 column cuts (0
 active)  in 0.084 seconds - new frequency is -100
 Cbc0014I Cut generator 6 (TwoMirCuts) - 159 row cuts, 0 column cuts (0
 active)  in 0.168 seconds - new frequency is -100
 Cbc0010I After 0 nodes, 1 on tree, 1e+50 best solution, best possible 6
 (12.96 seconds)
 Segmentation fault
 }}}

 The problem can be downloaded from
 http://www.icmc.usp.br/~alysson/files/share/sol21.lp
 I also attached the file to this issue.

-- 
Ticket URL: <https://projects.coin-or.org/Cbc/ticket/70>
COIN-OR Branch-and-Cut MIP Solver <http://projects.coin-or.org/Cbc>
An LP-based branch-and-cut MIP solver.