[Clp] cbc segmentation fault

[Victor Miller]

I tried to run the file
http://www.dei.unipd.it/~fisch/knuth_corrected.lpthrough cbc version
2.7.5 both on my Redhat Linux system at work and my
macbook running Mountain Lion at home.  In both cases I built it from the
latest source (as part of CoinAll).  First, cbc is a little more picky
than, say glpk, in that it didn't like the input.  It took me a while
(since the error messages didn't specify a line number where it thought
that there was an error!) to correct it by inserting white space in between
coefficients and variable names and in between >= and the value on the
right hand side.  However, once I gave the corrected version to cbc, it
eventually segment faulted.  This is definitely a bug!  Here's the output
from my Linux system.

Victor

cbc knuth_corrected.lp
Welcome to the CBC MILP Solver
Version: 2.7.5
Build Date: Sep 10 2012

command line - cbc knuth_corrected.lp (default strategy 1)
Continuous objective value is 13793 - 0.00 seconds
Cgl0003I 0 fixed, 52 tightened bounds, 0 strengthened rows, 0 substitutions
Cgl0004I processed model has 44 rows, 52 columns (52 integer) and 149
elements
Objective coefficients multiple of
2
Cutoff increment increased from 1e-05 to
1.998
Cbc0031I 16 added rows had average density of
16.3125
Cbc0013I At root node, 16 cuts changed objective from 14277 to 18872.054 in
100
passes

Cbc0014I Cut generator 0 (Probing) - 0 row cuts average 0.0 elements, 6
column cuts (6 active)  in 0.009 seconds - new frequency is
1
Cbc0014I Cut generator 1 (Gomory) - 1721 row cuts average 25.2 elements, 0
column cuts (16 active)  in 0.032 seconds - new frequency is
1
Cbc0014I Cut generator 2 (Knapsack) - 0 row cuts average 0.0 elements, 0
column cuts (0 active)  in 0.011 seconds - new frequency is
-100
Cbc0014I Cut generator 3 (Clique) - 0 row cuts average 0.0 elements, 0
column cuts (0 active)  in 0.000 seconds - new frequency is
-100
Cbc0014I Cut generator 4 (MixedIntegerRounding2) - 38 row cuts average 3.0
elements, 0 column cuts (0 active)  in 0.005 seconds - new frequency is
-100
Cbc0014I Cut generator 5 (FlowCover) - 0 row cuts average 0.0 elements, 0
column cuts (0 active)  in 0.007 seconds - new frequency is
-100
Cbc0014I Cut generator 6 (TwoMirCuts) - 303 row cuts average 7.2 elements,
0 column cuts (0 active)  in 0.014 seconds - new frequency is
-100
Cbc0010I After 0 nodes, 1 on tree, 1e+50 best solution, best possible
18872.054 (0.16
seconds)
Cbc0012I Integer solution of 27646 found by rounding after 13872 iterations
and 123 nodes (1.35
seconds)
Cbc0038I Full problem 44 rows 52 columns, reduced to 3 rows 4
columns
Cbc0012I Integer solution of 27546 found by RINS after 13872 iterations and
123 nodes (1.35
seconds)
Cbc0038I Full problem 44 rows 52 columns, reduced to 43 rows 46
columns
Cbc0012I Integer solution of 23196 found by combine solutions after 13872
iterations and 123 nodes (1.57
seconds)
Cbc0012I Integer solution of 23096 found by combine solutions after 13954
iterations and 124 nodes (1.57
seconds)
Cbc0038I Full problem 44 rows 52 columns, reduced to 41 rows 41
columns
Cbc0038I Full problem 44 rows 52 columns, reduced to 41 rows 41
columns
Cbc0012I Integer solution of 22996 found by RINS after 25086 iterations and
518 nodes (3.38
seconds)
Cbc0038I Full problem 44 rows 52 columns, reduced to 34 rows 37
columns
Cbc0010I After 1000 nodes, 94 on tree, 22996 best solution, best possible
21301.043 (7.26
seconds)
Cbc0038I Full problem 44 rows 52 columns, reduced to 37 rows 40
columns
Cbc0038I Full problem 44 rows 52 columns, reduced to 41 rows 40
columns
Cbc0038I Full problem 44 rows 52 columns, reduced to 41 rows 38
columns
Cbc0038I Full problem 44 rows 52 columns, reduced to 38 rows 38
columns
Cbc0010I After 2000 nodes, 79 on tree, 22996 best solution, best possible
21480.243 (13.75 seconds)
Cbc0038I Full problem 44 rows 52 columns, reduced to 32 rows 31 columns
Cbc0010I After 3000 nodes, 64 on tree, 22996 best solution, best possible
21480.243 (15.80 seconds)
Cbc0010I After 4000 nodes, 48 on tree, 22996 best solution, best possible
21480.243 (17.54 seconds)
Cbc0010I After 5000 nodes, 50 on tree, 22996 best solution, best possible
21480.243 (19.59 seconds)
Cbc0010I After 6000 nodes, 46 on tree, 22996 best solution, best possible
21503.428 (21.50 seconds)
Cbc0010I After 7000 nodes, 54 on tree, 22996 best solution, best possible
21503.428 (23.06 seconds)
Cbc0038I Full problem 44 rows 52 columns, reduced to 41 rows 40 columns
Cbc0010I After 8000 nodes, 53 on tree, 22996 best solution, best possible
21503.428 (24.77 seconds)
Cbc0038I Full problem 44 rows 52 columns, reduced to 41 rows 40 columns
Cbc0038I Full problem 44 rows 52 columns, reduced to 41 rows 38 columns
Cbc0010I After 9000 nodes, 45 on tree, 22996 best solution, best possible
21503.428 (26.55 seconds)
Cbc0038I Full problem 44 rows 52 columns, reduced to 41 rows 39 columns
Cbc0010I After 10000 nodes, 50 on tree, 22996 best solution, best possible
21503.428 (28.31 seconds)
Cbc0010I After 11000 nodes, 44 on tree, 22996 best solution, best possible
21747.031 (30.30 seconds)
Segmentation fault (core dumped)
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