[Pkg-scicomp-devel] Bug#490288: glpk: Fails on assertion

[Rafael Laboissiere]

[ This is in the context of:
  http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=490288 ]

* Andrew Makhorin <mao at gnu.org> [2008-07-12 18:06]:

> Saturday, July 12, 2008, 5:56:31 PM, you wrote:
> 
> > Does this mean that the problem is in the formulation of that specific
> > example or is it a bug in GLPK? If the later is the case, are you
> > planning to fix it?
> 
> It is a bug in the sense that the mip solver should return GLP_EFAIL
> rather than cause abnormal termination. The bug will be fixed in a next
> version of the package.

I just tried GLPK 4.30 and it seems that the bug is still present (see
below).  Am I doing something wrong, or is the bug really not fixed yet?

Cheers,

Rafael

===========================================================================

$ cat /var/tmp/bug.mod
var x1 integer;
var x2 integer;

minimize objective : x1 + x2;

s.t. constraint : (8^4 - 1) * x1 - 8^4 * x2 = 0;

s.t. x1NotNegative : x1 >= 1;
s.t. x2NotNegative : x2 >= 1;

end;
$ glpsol -m /var/tmp/bug.mod -o /var/tmp/bug.sol
Reading model section from /var/tmp/bug.mod...
11 lines were read
Generating objective...
Generating constraint...
Generating x1NotNegative...
Generating x2NotNegative...
Model has been successfully generated
glp_simplex: original LP has 4 rows, 2 columns, 6 non-zeros
Objective value = 2.0002442
OPTIMAL SOLUTION FOUND BY LP PRESOLVER
Integer optimization begins...
+     0: mip =     not found yet >=              -inf        (1; 0)
Assertion failed: x >= lb
Error detected in file glpios03.c at line 257
Aborted
$ glpsol --version | grep GLPSOL
GLPSOL: GLPK LP/MIP Solver 4.30