Fixed Issues in Gurobi Optimizer 12.0 #

Fixed floating point exception with POW constraints

Fixed an integer overflow when reading an attr file

Fixed an issue with an infinite violation on nonlinear models that have poles in POW constraints

Fixed an issue with returning a solution value of x=0 for a LOG constraint

Fixed wrong declaration of infeasibility on models with piecewise-linear objective

Fixed numerical issues with handling TAN functions

Fixed wrong answer bug in PreQLinearize handling of maximization problems with quadratic objective

Fixed performance issue in presolve for MINLPs if too many redundant constraints are detected

Fixed a UMR in MINLP presolve

Fixed possible segmentation fault in presolve for models with quadratic objective

Fixed bug that solving a model with multiple scenarios and multiple starts returns an error

Fixed issue with variable hints not being used in the model fingerprint calculation if hint priorities are not set

Fixed issue with variable hints not being written to the attribute file if hint priorities are not set

Fixed rare segmentation fault in heuristic for models with variable hints and numerically problematic LP relaxations

Fixed integer overflow in simplex memory allocation that results in a false out-of-memory error

Reduced performance and memory overhead in some situations for MIP models with disconnected components

Fixed possible segmentation fault for MIP models with disconnected components

Fixed numerical issue in the parallel row presolve reduction that could lead to a solution with large violation

Fixed issue for MIP models with disconnected components that could lead to wrong answers

Fixed potential segmentation fault in simplex algorithm

Fixed bug with dual simplex incorrectly returning an error 10025 for models with more than 2 billion nonzeros

Fixed wrong declaration of unboundedness on small nonconvex QP

Fixed issue that providing a warm start but setting LPWarmStart=0 takes a different simplex solving path than omitting the warm start

Fixed bug with implied bound computation for quadratic constraints that could lead to wrong answers

Fixed numerical issue in IIS algorithm that could lead to a wrong IIS result

Fixed bug in presolve reduction that detects an XOR structure, which could lead to wrong answers

Fixed numerical issue with an unbounded nonconvex MIQCP that was declared optimal

Fixed heap-buffer-overflow in mps reader when reading multi-scenario names

Fixed numerical issue in simplex that could lead to a seemingly infinite loop

Fixed error code returned from GRBstartenv when trying to use a Compute Server with a light Gurobi client library

Fixed potential segmentation fault on nonconvex models caused by nonlinear barrier algorithm

Fixed very rare performance bug in presolve aggregator

Fixed inconsistency in C++ API for the default value of abstol in setObjectiveN method

Fixed ConvertToFixed method in .NET API

Fixed convertToFixed method in Java API

Fixed issue in Maven pom file that leads to a warning or error about an invalid Gurobi pom file

Added DYLD_LIBRARY_PATH to MacOS examples Makefile

Fixed issue in tuning tool where Gurobi would not switch to the RUNTIME criterion after it found a parameter setting that could solve all models to optimality

Missing GRBloadenv and GRBemptyenv symbols in the C library have been restored

Fixed bug and numerical issue in domain propagation of LOGISTIC and TAN functions

Fixed bug in presolve that can lead to wrong objective value calculation

Fixed bug with incorrect SolCount attribute value when using the PoolGap parameter

Fixed bug in object oriented APIs with duplicate variable indices in the objective functions of multi-objective models

Fixed numerical issue with reporting a feasible solution to the user while the problem was already declared infeasible

Fixed rare uninitialized memory read when accessing the simplex basis, which may lead to non-deterministic behavior

Fixed performance bug in multi-objective solves when crushing an objective function into the presolved model space

Fixed issue in multi-objective solves that can lead to unexpected error code 20000

Fixed very rare segmentation fault when using node files

Fixed bug with nonlinear presolve reductions invalidating lazy constraints produced in the callback

Fixed bug in the tuning tool used with a WLS license

Fixed unexpected error 10005 after multi-objective solve

Fixed bug in simplex-internal reduced cost strengthening that can lead to wrong answers for MIP models

Use safer numerics in domain propagation of quadratic constraints to avoid numerical issues

Fixed issue where the MIPGap setting could lead to a path change in the MIP tree search

Fixed infinite loop in IIS algorithm resulting from numerical issues in a sub-system solve

Fixed behavior of GRBpresolvemodel and Model.presolve methods when a restart is triggered during presolve

Fixed numerical issue in domain propagation of linear constraints with very small coefficients that can lead to wrong answers

Fixed bug with missing error messages when model size exceeds license limits

Fixed issues in presolve with handling the DIVIDE operator in general nonlinear functions

Fixed numerical issue in mixing path cut separator that could lead to wrong answers

Fixed bug in implicitly handling lower bounds in cone constraints that can lead to sub-optimal termination for infeasible SOCPs

Fixed segmentation fault with using MIP starts on MINLP models

Fixed bug that leads to invocation of Model.cbStopOneMultiObj terminating multi-objective solves completely

Fixed bug in presolve for quadratic constraints that could lead to wrong answers for MIQCPs

Model.addConstr now raises an explicit exception for invalid syntax involving NL constraints

Fixed error message in gurobipy when trying to optimize again an asynchronously optimized model that has already been closed

Fixed bug in presolve for QUBO models and PoolSearchMode=2 that leads to not anymore finding all feasible solutions

Fixed bug in presolve with non-convex quadratic constraints being modeled as general nonlinear constraints always leading to non-PSD error even if non-convex constraints should be allowed

Fixed bug with ignoring resource parameter limits like Threads or MemLimit with multi-objective or concurrent environments

Fixed bug with ignoring lazy constraints from the callback if the callback calls Model.message .

Removed warning about big bounds that had been introduced by Gurobi during presolve

Fixed memory leak in barrier when presolve decided to explicitly dualize the model

Fixed potential segmentation fault with general nonlinear constraints containing plus and mult operators

Fixed numerical issue in Euclidean presolve reduction that could lead to wrong answers

Fixed constraint sense in gc_funcnonlinear example for MATLAB and R

Fixed numerical issue in the envelope calculation for SIN and COS nonlinear function constraints

Fixed numerical issue for POLY nonlinear function constraints with tiny coefficients

Fixed numerical issue in a presolve reduction that detects piece-wise linear objectives, which can lead to wrong answers

Fixed potential segmentation fault in presolve for general nonlinear constraints

Fixed numerical issue in presolve for cliques with continuous variables

Fixed potential segmentation fault in a very rarely called heuristic

Fixed issue that fingerprint attribute for a model with piece-wise linear objective function on macOS ARM can be different than on other platforms.

Properly sign Windows dll and executables and .NET library

Fixed issue with empty error messages for function calls from callback

Fixed issue with infinite recursion if GRBmsg is called from within a message callback

Reduced number of malloc calls to avoid issues with memory fragmentation that may lead to out-of-memory errors

Removed runtime overhead from querying OS information for logging that could be noticed when solving thousands of tiny models

Fixed a potential segmentation fault when setting an integer attribute of a general constraint

Fixed read error for OPB files at the end of the file

Fixed issue in OPB file reader when the resulting quadratic problem has more than 2 billion quadratic terms

Fixed very rare numerical issue in presolve that could lead to wrong answers

Fixed numerical issues in presolve that could lead to a wrong declaration of infeasibility

Fixed numerical issues in parallel column presolve reduction that could lead to wrong answers

Fixed issue with inconsistent objective values if uncrushing improves (for numerical reasons) the objective value

Fixed rare issue with presolve reduction that combines an inequality with an equation that is parallel to it, leading to a wrong answer

Fixed issue in presolve with general piecewise-linear constraint that can lead to large constraint violations

Fixed potential segmentation fault in presolve for models with both quadratic equalities and a quadratic objective

Fixed rare issues in MIQCP presolve that could lead to wrong answers

Fixed some numerical issues in the simplex algorithm

Fixed numerical issue in dependent row presolve for LPs that could lead to wrong declaration of infeasibility

Fixed issue with infinite cycling in QP simplex

Fixed very rare issue with super basic variables handling in LP relaxations of MIPs that could lead to wrong answers

Fixed memory leak in simplex when switching from primal to dual and solving again with primal

Fixed issue with dual violations if a continuous model with a piecewise-linear objective is solved by barrier without crossover

Fixed bugs in barrier that could arise for models with more than 2 billion non-zeros

Fixed potential segmentation fault in SOCP when there are more cones than linear constraints in the model

Fixed issue with wrong objective sense for maximization models that are solved with barrier, use the explicit dual model and exploit symmetry

Fixed issue with IntegralityFocus=1 that could lead to a wrong answer

Fixed issue in MIP cleanup with accepting a solution that has too large constraint violations

Fixed numerical issue in cut lifting that could lead to wrong answers

Fixed very rare segmentation fault in a special case of clique and implied bound cuts

Fixed performance issue with the interior point heuristic for nonconvex MIQCPs not benefitting from the user-specified PStart values because they are incorrectly discarded

Fixed issue with an infinite loop in MIQCP solving if outer approximation is unbounded

Fixed numerical issue with small values in presolve for quadratic constraints that could lead to wrong answers

Fixed bug with spatial branching for nonconvex models that could result in excessively large node files or memory consumption

Raise error earlier if there are more than 2 billion quadratic terms in the quadratic constraints

Removed wrong warning log message about piecewise-linear objective for an IIS solve on a model with general function constraints

Fixed issue with incorrect handling of the WorkLimit parameter in individual multi-objective environments

Fixed issues with getting a wrong primary objective function in a multi-objective model without an update call before setting the secondary objective

Fixed inconsistencies in the interplay of the global Threads parameter and the Threads parameters of concurrent environments

Fixed handling of fixed parameter settings in remote tuning sessions

Fixed usage of np.array() for numpy 2.0 compatibility