[Scip] Problem with SCIP_OBJSENSE_MAXIMIZE

[Rostislav Stanek]

Dear SCIP community,

I have the following problem:

By solving a minimization problem described as an ILP everything is 
working fine. Then I changed the signs by all objective function 
coefficients in order to obtain the corresponding maximization problem 
and everything is working fine as well. But by using the option

SCIPsetObjsense(sCIP, SCIP_OBJSENSE_MAXIMIZE);

an error occurs:

src/lpi/lpi_cpx.c:3900: SCIPlpiGetNorms: Assertion `lpi->messagehdlr != 
((void *)0)' failed.

Program received signal SIGABRT, Aborted.
0x00007ffff694f0d5 in __GI_raise (sig=<optimized out>) at 
../nptl/sysdeps/unix/sysv/linux/raise.c:64
64    ../nptl/sysdeps/unix/sysv/linux/raise.c: Adresář nebo soubor 
neexistuje.
(gdb) bt
#0  0x00007ffff694f0d5 in __GI_raise (sig=<optimized out>) at 
../nptl/sysdeps/unix/sysv/linux/raise.c:64
#1  0x00007ffff695283b in __GI_abort () at abort.c:91
#2  0x00007ffff6947d9e in __assert_fail_base (fmt=<optimized out>, 
assertion=0x1711318 "lpi->messagehdlr != ((void *)0)",
     file=0x17104d8 "src/lpi/lpi_cpx.c", line=<optimized out>, 
function=<optimized out>) at assert.c:94
#3  0x00007ffff6947e42 in __GI___assert_fail (assertion=0x1711318 
"lpi->messagehdlr != ((void *)0)", file=0x17104d8 "src/lpi/lpi_cpx.c", 
line=3900,
     function=0x17116a0 "SCIPlpiGetNorms") at assert.c:103
#4  0x0000000000ab6b73 in SCIPlpiGetNorms (lpi=0x22ccfd0, 
blkmem=0x20a4640, lpinorms=0x22da8a8) at src/lpi/lpi_cpx.c:3900
#5  0x000000000054a087 in SCIPlpGetNorms (lp=0x22bf8b0, 
blkmem=0x20a4640, lpinorms=0x22da8a8) at src/scip/lp.c:12228
#6  0x00000000006c18d9 in SCIPtreeStartProbing (tree=0x22da830, 
blkmem=0x20a4640, set=0x20a6660, lp=0x22bf8b0, strongbranching=0)
     at src/scip/tree.c:5954
#7  0x0000000000656258 in SCIPstartProbing (scip=0x209d360) at 
src/scip/scip.c:29494
#8  0x0000000000911c84 in performRandRounding (scip=0x209d360, 
heurdata=0x2201490, sol=0x2327910, cands=0x2b4dea0, ncands=62, propagate=1,
     result=0x7fffffffc818) at src/scip/heur_randrounding.c:94
#9  0x0000000000912707 in performLPRandRounding (scip=0x209d360, 
heurdata=0x2201490, heurtiming=2, propagate=1, result=0x7fffffffc818)
     at src/scip/heur_randrounding.c:320
#10 0x0000000000912d9c in heurExecRandrounding (scip=0x209d360, 
heur=0x2201520, heurtiming=2, nodeinfeasible=0, result=0x7fffffffc818)
     at src/scip/heur_randrounding.c:458
#11 0x000000000051060a in SCIPheurExec (heur=0x2201520, set=0x20a6660, 
primal=0x22da7a0, depth=0, lpstateforkdepth=-1, heurtiming=2,
     nodeinfeasible=0, ndelayedheurs=0x7fffffffc81c, 
result=0x7fffffffc818) at src/scip/heur.c:454
#12 0x0000000000699d8d in SCIPprimalHeuristics (set=0x20a6660, 
stat=0x209d450, prob=0x22db820, primal=0x22da7a0, tree=0x22da830, 
lp=0x22bf8b0,
     nextnode=0x0, heurtiming=2, nodeinfeasible=0, 
foundsol=0x7fffffffc9b0) at src/scip/solve.c:313
#13 0x00000000006a0c82 in priceAndCutLoop (blkmem=0x20a4640, 
set=0x20a6660, messagehdlr=0x0, stat=0x209d450, transprob=0x22db820,
     origprob=0x209e020, primal=0x22da7a0, tree=0x22da830, lp=0x22bf8b0, 
pricestore=0x2301e70, sepastore=0x2389280, cutpool=0x231f270,
     delayedcutpool=0x2302030, branchcand=0x22c1e10, conflict=0x22daa20, 
eventfilter=0x22b6040, eventqueue=0x225a3c0, initiallpsolved=0,
     cutoff=0x7fffffffd02c, unbounded=0x7fffffffd030, 
lperror=0x7fffffffce54, pricingaborted=0x7fffffffce50) at 
src/scip/solve.c:2271
#14 0x00000000006a3013 in solveNodeLP (blkmem=0x20a4640, set=0x20a6660, 
messagehdlr=0x0, stat=0x209d450, origprob=0x209e020, transprob=0x22db820,
     primal=0x22da7a0, tree=0x22da830, lp=0x22bf8b0, 
pricestore=0x2301e70, sepastore=0x2389280, cutpool=0x231f270, 
delayedcutpool=0x2302030,
     branchcand=0x22c1e10, conflict=0x22daa20, eventfilter=0x22b6040, 
eventqueue=0x225a3c0, initiallpsolved=0, newinitconss=0, 
cutoff=0x7fffffffd02c,
     unbounded=0x7fffffffd030, lperror=0x7fffffffce54, 
pricingaborted=0x7fffffffce50) at src/scip/solve.c:2788
#15 0x00000000006a5513 in propAndSolve (blkmem=0x20a4640, set=0x20a6660, 
messagehdlr=0x0, stat=0x209d450, origprob=0x209e020, transprob=0x22db820,
     primal=0x22da7a0, tree=0x22da830, lp=0x22bf8b0, 
relaxation=0x22d9110, pricestore=0x2301e70, sepastore=0x2389280, 
branchcand=0x22c1e10,
     cutpool=0x231f270, delayedcutpool=0x2302030, conflict=0x22daa20, 
eventfilter=0x22b6040, eventqueue=0x225a3c0, focusnode=0x2306ff0, 
actdepth=0,
     timingmask=1, propagate=1, solvelp=1, solverelax=1, 
forcedlpsolve=0, nlperrors=0x7fffffffce30, fullpropagation=0x7fffffffce48,
     propagateagain=0x7fffffffce44, initiallpsolved=0x7fffffffce38, 
solvelpagain=0x7fffffffce40, solverelaxagain=0x7fffffffce3c,
     cutoff=0x7fffffffd02c, unbounded=0x7fffffffd030, 
lperror=0x7fffffffce54, pricingaborted=0x7fffffffce50, 
forcedenforcement=0x7fffffffce58)
     at src/scip/solve.c:3442

Can you help me / explain it?

Thank you for your response in advance.

Yours sincerely,
Rostislav Stanek