SCIP tests fail when using CLP as the solver

[adbuerger]

Hello everyone,

when I compile SCIP 9.2.1 to use CLP as LP solver (on Debian 12, using the CLP-version 1.17.6-3 shipped via apt), I can see a number of failing tests which I wanted to inform you about:

99% tests passed, 14 tests failed out of 1693

[...]

The following tests FAILED:
	575 - Indicator-indicatorlogicorsepa-mcf128-4-1.lp (Subprocess aborted)
	584 - Indicator-indicatorlogicorsepa-mcf64-4-1.lp (Subprocess aborted)
	1353 - Issue-default-3722.cip (Failed)
	1629 - examples-vrp-eil13 (Subprocess aborted)
	1681 - GCG-BPP-default-N1C1W4_M.BPP.lp (Failed)
	1682 - GCG-BPP-default-N1C2W2_O.BPP.lp (Failed)
	1683 - GCG-BPP-default-N1C3W1_A.lp (Failed)
	1684 - GCG-CPMP-default-p1250-2.lp (Failed)
	1685 - GCG-CPMP-default-p1650-2.txt.lp (Failed)
	1686 - GCG-CPMP-default-p2050-1.txt.lp (Failed)
	1687 - GCG-CS-default-TEST0055.lp (Failed)
	1688 - GCG-CS-default-TEST0059.lp (Failed)
	1689 - GCG-GAP-default-gap4_2.txt.lp (Failed)
	1690 - GCG-GAP-default-gap8_4.txt.lp (Failed)
Errors while running CTest

To gather more details, I re-ran the failed tests using ctest --rerun-failed, this is the output:

Test project /path/to/scipoptsuite-9.2.1/build
      Start  575: Indicator-indicatorlogicorsepa-mcf128-4-1.lp
 1/14 Test  #575: Indicator-indicatorlogicorsepa-mcf128-4-1.lp ...Subprocess aborted***Exception:   0.17 sec
      Start  584: Indicator-indicatorlogicorsepa-mcf64-4-1.lp
 2/14 Test  #584: Indicator-indicatorlogicorsepa-mcf64-4-1.lp ....Subprocess aborted***Exception:   0.09 sec
      Start 1353: Issue-default-3722.cip
 3/14 Test #1353: Issue-default-3722.cip .........................***Failed  Error regular expression found in output. Regex=[ERROR|user parameter file </path/to/scipoptsuite-9.2.1/scip/check/coverage/settings/default.set> not found]  0.12 sec
      Start 1629: examples-vrp-eil13
 4/14 Test #1629: examples-vrp-eil13 .............................Subprocess aborted***Exception:   0.27 sec
      Start 1681: GCG-BPP-default-N1C1W4_M.BPP.lp
 5/14 Test #1681: GCG-BPP-default-N1C1W4_M.BPP.lp ................***Failed  Required regular expression not found. Regex=[Validation         : Success
]  0.20 sec
      Start 1682: GCG-BPP-default-N1C2W2_O.BPP.lp
 6/14 Test #1682: GCG-BPP-default-N1C2W2_O.BPP.lp ................***Failed  Required regular expression not found. Regex=[Validation         : Success
]  0.14 sec
      Start 1683: GCG-BPP-default-N1C3W1_A.lp
 7/14 Test #1683: GCG-BPP-default-N1C3W1_A.lp ....................***Failed  Required regular expression not found. Regex=[Validation         : Success
]  0.09 sec
      Start 1684: GCG-CPMP-default-p1250-2.lp
 8/14 Test #1684: GCG-CPMP-default-p1250-2.lp ....................***Failed  Required regular expression not found. Regex=[Validation         : Success
]  0.16 sec
      Start 1685: GCG-CPMP-default-p1650-2.txt.lp
 9/14 Test #1685: GCG-CPMP-default-p1650-2.txt.lp ................***Failed  Required regular expression not found. Regex=[Validation         : Success
]  0.28 sec
      Start 1686: GCG-CPMP-default-p2050-1.txt.lp
10/14 Test #1686: GCG-CPMP-default-p2050-1.txt.lp ................***Failed  Required regular expression not found. Regex=[Validation         : Success
]  0.15 sec
      Start 1687: GCG-CS-default-TEST0055.lp
11/14 Test #1687: GCG-CS-default-TEST0055.lp .....................***Failed  Required regular expression not found. Regex=[Validation         : Success
]  0.06 sec
      Start 1688: GCG-CS-default-TEST0059.lp
12/14 Test #1688: GCG-CS-default-TEST0059.lp .....................***Failed  Required regular expression not found. Regex=[Validation         : Success
]  0.06 sec
      Start 1689: GCG-GAP-default-gap4_2.txt.lp
13/14 Test #1689: GCG-GAP-default-gap4_2.txt.lp ..................***Failed  Required regular expression not found. Regex=[Validation         : Success
]  0.11 sec
      Start 1690: GCG-GAP-default-gap8_4.txt.lp
14/14 Test #1690: GCG-GAP-default-gap8_4.txt.lp ..................***Failed  Required regular expression not found. Regex=[Validation         : Success
]  0.04 sec

A closer look at the output of ctest --rerun-failed --output-on-failure for the tests that state "Subprocess aborted" reveal the following error messages during these tests:

1/14: scip: ClpPackedMatrix.cpp:4944: virtual bool ClpPackedMatrix::allElementsInRange(ClpModel*, double, double, int): Assertion `model->clpScaledMatrix()->getNumElements() == matrix_->getNumElements()' failed.

2/14: scip: ClpPackedMatrix.cpp:4944: virtual bool ClpPackedMatrix::allElementsInRange(ClpModel*, double, double, int): Assertion `model->clpScaledMatrix()->getNumElements() == matrix_->getNumElements()' failed.

4/14: vrp: ClpPackedMatrix.cpp:4944: virtual bool ClpPackedMatrix::allElementsInRange(ClpModel*, double, double, int): Assertion `model->clpScaledMatrix()->getNumElements() == matrix_->getNumElements()' failed.

For comparison, I ran SCIP with SoPlex and I cannot see any failing tests then (0 tests failed out of 1693).

Thank you for your work on this very useful software and project!

[ambros-gleixner]

Thank you for testing and reporting! We do not actively maintain the clp interface, but it works well for some people, so we keep it around. Probably it does not make sense to keep this issue open. We will dedicate the time we have rather on the lpi_highs interface.

[svigerske]

Much less failures than I had expected. Might be an issue when columns are added to the LP.

@pfetsch once raised some hope that @jjhforrest could look into it. :-)

Version 1.17.6 is already 5 years old, though.