Handle cuOpt UnboundedOrInfeasible termination status (11) by rgsl888prabhu · Pull Request #3916 · Pyomo/pyomo

rgsl888prabhu · 2026-04-16T21:35:14Z

Summary

cuOpt added a new termination status (value 11, `UnboundedOrInfeasible`) that its presolver returns when it cannot disambiguate infeasibility from unboundedness. The `cuopt_direct` plugin's status cascade does not recognize it, so it falls through to `TerminationCondition.error` and fails the `LP_unbounded` test variants (`test_cuopt_python`, `test_cuopt_python_nonsymbolic_labels`, `test_cuopt_python_symbolic_labels`).

Adds an `elif status == 11` branch mapping to `TerminationCondition.infeasibleOrUnbounded` (with `SolverStatus.warning` / `SolutionStatus.unsure`). Also extends the status-code comment block to include status 10 (WorkLimit) and 11 (UnboundedOrInfeasible).

Tracked upstream in NVIDIA/cuopt#1114.

cuOpt added a new termination status (value 11, UnboundedOrInfeasible) that the PSLP presolver returns when it cannot disambiguate infeasibility from unboundedness. The cuopt_direct plugin's status cascade did not recognize it, falling through to TerminationCondition.error and failing any LP_unbounded test. Adds an elif branch mapping status 11 to TerminationCondition. infeasibleOrUnbounded (with SolverStatus.warning / SolutionStatus.unsure). Also extends the status-code comment block to include status 10 (WorkLimit) and 11 (UnboundedOrInfeasible) for documentation. Tracked in NVIDIA/cuopt#1114. Signed-off-by: Ramakrishna Prabhu <ramakrishnap@nvidia.com>

jsiirola · 2026-04-17T17:10:45Z

This looks reasonable. Can you add a a test that exercises this result from cuOpt?

codecov · 2026-04-17T18:18:58Z

Codecov Report

❌ Patch coverage is 0% with 4 lines in your changes missing coverage. Please review.
✅ Project coverage is 89.93%. Comparing base (34a3877) to head (326e154).

Files with missing lines	Patch %	Lines
pyomo/solvers/plugins/solvers/cuopt_direct.py	0.00%	4 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3916      +/-   ##
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- Misses      10709    10716       +7

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An unbounded LP with no variable bounds triggers cuOpt's presolver to return UnboundedOrInfeasible (status 11); the test asserts the plugin maps it to TerminationCondition.infeasibleOrUnbounded, SolverStatus.warning, and SolutionStatus.unsure.

jsiirola · 2026-04-18T04:55:03Z

Note: the test appears to require a specific version of cuOpt:

18:21:10 ________________ CUOPTTests.test_unbounded_or_infeasible_status ________________
18:21:10 
18:21:10 self = <pyomo.solvers.tests.checks.test_cuopt_direct.CUOPTTests testMethod=test_unbounded_or_infeasible_status>
18:21:10 
18:21:10     @unittest.skipIf(not cuopt_available, "The CuOpt solver is not available")
18:21:10     def test_unbounded_or_infeasible_status(self):
18:21:10         # An LP with no variable bounds and an unbounded objective triggers
18:21:10         # cuOpt's presolver to return UnboundedOrInfeasible (status 11), which
18:21:10         # the plugin maps to TerminationCondition.infeasibleOrUnbounded.
18:21:10         m = ConcreteModel()
18:21:10         m.x = Var()
18:21:10         m.y = Var()
18:21:10         m.obj = Objective(expr=m.x + m.y, sense=minimize)
18:21:10     
18:21:10         opt = SolverFactory('cuopt')
18:21:10         res = opt.solve(m, load_solutions=False)
18:21:10     
18:21:10 >       self.assertEqual(res.solver.termination_condition, "infeasibleOrUnbounded")
18:21:10 E       AssertionError: <TerminationCondition.unbounded: 'unbounded'> != 'infeasibleOrUnbounded'
18:21:10 
18:21:10 pyomo/pyomo/solvers/tests/checks/test_cuopt_direct.py:141: AssertionError
18:21:10 ----------------------------- Captured stdout call -----------------------------
18:21:10 Setting parameter log_file to /tmp/tmpalrh5rvw.log
18:21:10 cuOpt version: 25.10.0, git hash: 99e549c, host arch: x86_64, device archs: 70-real,75-real,80-real,86-real,90a-real,100f-real,120a-real,120
18:21:10 CPU: Intel(R) Xeon(R) Silver 4410Y, threads (physical/logical): 12/24, RAM: 4.94 GiB
18:21:10 CUDA 12.9, device: NVIDIA T400 4GB (ID 0), VRAM: 3.63 GiB
18:21:10 CUDA device UUID: 
18:21:10 
18:21:10 Solving a problem with 1 constraints, 2 variables (0 integers), and 1 nonzeros
18:21:10 Problem scaling:
18:21:10 Objective coefficents range:          [1e+00, 1e+00]
18:21:10 Constraint matrix coefficients range: [0e+00, 0e+00]
18:21:10 Constraint rhs / bounds range:        [0e+00, 0e+00]
18:21:10 Variable bounds range:                [0e+00, 0e+00]
18:21:10 
18:21:10 Third-party presolve is disabled, skipping
18:21:10 Objective offset 0.000000 scaling_factor 1.000000
18:21:10 Running concurrent
18:21:10 
18:21:10 Dual simplex finished in 0.00 seconds, total time 0.00
18:21:10 Barrier finished in 0.00 seconds
18:21:10    Iter    Primal Obj.      Dual Obj.    Gap        Primal Res.  Dual Res.   Time
18:21:10       0 +0.00000000e+00 +0.00000000e+00  0.00e+00   0.00e+00     1.41e+00   0.017s
18:21:10 PDLP finished
18:21:10 Dual Simplex Solve status Dual Infeasible
18:21:10 Concurrent time:  0.019s, total time 0.019s
18:21:10 Solved with dual simplex
18:21:10 Status: Dual Infeasible   Objective: -inf  Iterations: 0  Time: 0.019s

rgsl888prabhu · 2026-04-20T14:59:50Z

Note: the test appears to require a specific version of cuOpt:

18:21:10 ________________ CUOPTTests.test_unbounded_or_infeasible_status ________________
18:21:10 
18:21:10 self = <pyomo.solvers.tests.checks.test_cuopt_direct.CUOPTTests testMethod=test_unbounded_or_infeasible_status>
18:21:10 
18:21:10     @unittest.skipIf(not cuopt_available, "The CuOpt solver is not available")
18:21:10     def test_unbounded_or_infeasible_status(self):
18:21:10         # An LP with no variable bounds and an unbounded objective triggers
18:21:10         # cuOpt's presolver to return UnboundedOrInfeasible (status 11), which
18:21:10         # the plugin maps to TerminationCondition.infeasibleOrUnbounded.
18:21:10         m = ConcreteModel()
18:21:10         m.x = Var()
18:21:10         m.y = Var()
18:21:10         m.obj = Objective(expr=m.x + m.y, sense=minimize)
18:21:10     
18:21:10         opt = SolverFactory('cuopt')
18:21:10         res = opt.solve(m, load_solutions=False)
18:21:10     
18:21:10 >       self.assertEqual(res.solver.termination_condition, "infeasibleOrUnbounded")
18:21:10 E       AssertionError: <TerminationCondition.unbounded: 'unbounded'> != 'infeasibleOrUnbounded'
18:21:10 
18:21:10 pyomo/pyomo/solvers/tests/checks/test_cuopt_direct.py:141: AssertionError
18:21:10 ----------------------------- Captured stdout call -----------------------------
18:21:10 Setting parameter log_file to /tmp/tmpalrh5rvw.log
18:21:10 cuOpt version: 25.10.0, git hash: 99e549c, host arch: x86_64, device archs: 70-real,75-real,80-real,86-real,90a-real,100f-real,120a-real,120
18:21:10 CPU: Intel(R) Xeon(R) Silver 4410Y, threads (physical/logical): 12/24, RAM: 4.94 GiB
18:21:10 CUDA 12.9, device: NVIDIA T400 4GB (ID 0), VRAM: 3.63 GiB
18:21:10 CUDA device UUID: 
18:21:10 
18:21:10 Solving a problem with 1 constraints, 2 variables (0 integers), and 1 nonzeros
18:21:10 Problem scaling:
18:21:10 Objective coefficents range:          [1e+00, 1e+00]
18:21:10 Constraint matrix coefficients range: [0e+00, 0e+00]
18:21:10 Constraint rhs / bounds range:        [0e+00, 0e+00]
18:21:10 Variable bounds range:                [0e+00, 0e+00]
18:21:10 
18:21:10 Third-party presolve is disabled, skipping
18:21:10 Objective offset 0.000000 scaling_factor 1.000000
18:21:10 Running concurrent
18:21:10 
18:21:10 Dual simplex finished in 0.00 seconds, total time 0.00
18:21:10 Barrier finished in 0.00 seconds
18:21:10    Iter    Primal Obj.      Dual Obj.    Gap        Primal Res.  Dual Res.   Time
18:21:10       0 +0.00000000e+00 +0.00000000e+00  0.00e+00   0.00e+00     1.41e+00   0.017s
18:21:10 PDLP finished
18:21:10 Dual Simplex Solve status Dual Infeasible
18:21:10 Concurrent time:  0.019s, total time 0.019s
18:21:10 Solved with dual simplex
18:21:10 Status: Dual Infeasible   Objective: -inf  Iterations: 0  Time: 0.019s

Status 11 was introduced in cuOpt v26.04.00 (PR #941, tagged 2026-04-09). The CI runs 25.10.0, so PSLP isn't available and status 11 is never produced

jsiirola · 2026-04-28T18:49:45Z

There are two things that are holding up this PR:

the test needs to be updated with a guard to skip if cuOpt is too old (@rgsl888prabhu)
the Jenkins infrastructure needs to be updated to test both new and old cuOpt (@jsiirola)

Failing tests need to be addressed

jsiirola · 2026-04-29T14:03:31Z

We are adopting a new review process where we convert PRs that are "waiting on the author" back to "draft" (to signal the PR state to both the author and the dev team). Please use the "Ready for review" button to signal the developers when it is time to get the PR back into the review queue.

cuOpt status 11 (UnboundedOrInfeasible) is produced by the presolver introduced in cuOpt 26.04. On older cuOpt the LP in the test reaches the simplex/PDLP path and is reported as TerminationCondition.unbounded instead, failing the assertion. Guard the test with a runtime version check via CUOPTDirect._version. Addresses review feedback on PR Pyomo#3916.

jsiirola added AT: PRE-TEST INSPECTED labels Apr 17, 2026

pyomo-autotest removed the AT: PRE-TEST INSPECTED label Apr 17, 2026

rgsl888prabhu and others added 2 commits April 17, 2026 13:19

Run black

326e154

blnicho previously approved these changes Apr 17, 2026

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blnicho added AT: PRE-TEST INSPECTED PR:need_additional_review labels Apr 17, 2026

pyomo-autotest removed the AT: PRE-TEST INSPECTED label Apr 17, 2026

blnicho removed the PR:need_additional_review label Apr 21, 2026

blnicho marked this pull request as draft April 29, 2026 05:36

rgsl888prabhu marked this pull request as ready for review April 29, 2026 15:15

Merge branch 'main' into cuopt-unboundedorinfeasible-status

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Handle cuOpt UnboundedOrInfeasible termination status (11)#3916

Handle cuOpt UnboundedOrInfeasible termination status (11)#3916
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