[Scip] Assertion: Objective limit not infinity in exact SCIP

[Kati Wolter]

Hi Matthias,

this assert comes up in the constraint handler that stores and handles the
exact problem (cons_exactlp.c). I will have a look at it (might be some
special case that is not handled yet).

Best, Kati



> Dear list,
>
> I came across the following problem: This ZPL model
>
> % cat obj-integral-bug.zpl
> var x integer;
>
> maximize cost: 1*x;
>
> subto row0: 1*x <= 1;
>
> produces the following assertion failure [1]. Is this indeed a bug or
> can I do something about this?
>
> Best regards,
>
> Matthias Walter
>
> [1] SCIP output:
>
> % ~/software/exact-scip/scip-3.0.0-ex/bin/scip.linux.x86_64.gnu.dbg.spx
> Using QSopt_ex (SVN-version 2.5.10:537, built Apr 20 2015-11:22:02)
> Using EGlib (SVN-version 2.6.20:559M, built Apr 20 2015-11:14:51)
> Using EG-GMP mempool
> SCIP version 3.0.0 [precision: 8 byte] [memory: block] [mode: debug] [LP
> solver: SoPlex 2.0.0] [Exact LP solver: QSopt_ex 2.5.10] [GitHash:
> e3f49b6]
> Copyright (c) 2002-2012 Konrad-Zuse-Zentrum fuer Informationstechnik
> Berlin (ZIB)
>
> External codes:
>   Readline 6.2         GNU library for command line editing
> (gnu.org/s/readline)
>   SoPlex 2.0.0         Linear Programming Solver developed at Zuse
> Institute Berlin (soplex.zib.de) [GitHash: 568f354]
>   QSopt_ex 2.5.10      Exact Linear Programming Solver by D. Espinoza,
> W. Cook, S. Dash, and D. Applegate
> (dii.uchile.cl/~daespino/QSoptExact_doc/main.html)
>   EGlib 2.6.20         Library for basic structures and utilities by D.
> Espinoza and M. Goycoolea (dii.uchile.cl/~daespino/EGlib_doc/main.html)
>   cppad-20120101.3     Algorithmic Differentiation of C++ algorithms
> developed by B. Bell (www.coin-or.org/CppAD)
>   ZLIB 1.2.3.4         General purpose compression library by J. Gailly
> and M. Adler (zlib.net)
>   GMP 5.0.2            GNU Multiple Precision Arithmetic Library
> developed by T. Granlund (gmplib.org)
>   MPFR 3.1.0-p3        GNU Multiple Precision Floating-Point Reliable
> Library (mpfr.org)
>   ZIMPL 3.3.2          Zuse Institute Mathematical Programming Language
> developed by T. Koch (zimpl.zib.de)
>
> Reduced version of SCIP in EXACT mode (version 1.0.0):
>   Algorithm: branch-and-bound
>   Constraints: exact linear
>   Branching: all standard plugins
>   Readers: zpl (mps files can be converted with "mps2zpl.sh
> filename.mps[.gz]")
>
> user parameter file <scip.set> not found - using default parameters
>
> SCIP> read obj-integral-bug.zpl
>
> read problem <obj-integral-bug.zpl>
> ============
>
>
> base directory for ZIMPL parsing: </home/xammy>
>
> original problem has 1 variables (0 bin, 1 int, 0 impl, 0 cont) and 1
> constraints
> SCIP> opt
>
> scip.linux.x86_64.gnu.dbg.spx: src/scip/cons_exactlp.c:2073:
> checkObjIntegral: Assertion `SCIPisInfinity(scip,
> SCIPgetObjlimit(scip))' failed.
> Aborted (core dumped)
> _______________________________________________
> Scip mailing list
> Scip at zib.de
> http://listserv.zib.de/mailman/listinfo/scip
>