Xintong Zhou

pulp does not work on COIN_CMD

2

I want to use pulp with COIN_CMD, but it does not work. For reference, PULP_CBC_CMD works fine, and `cbc` also works correctly from command line. Here is an example: ```...

HiGHS crashes with assertion failure

11

HiGHS (build from `latest` branch) crashes when solving [seed.mps.txt](https://github.com/user-attachments/files/19096127/seed.mps.txt) with option file [highs_options.txt](https://github.com/user-attachments/files/19096142/highs_options.txt) ``` root@b9f8d0525121:/tmp# cat highs_options.txt mip_rel_gap=0 mip_abs_gap=0 presolve=off mip_lp_age_limit=19 mip_pool_age_limit=2 mip_heuristic_effort=0.321638279322984 root@b9f8d0525121:/tmp# highs --model_file seed.mps --options_file highs_options.txt Running...

Inconsistent optimal results by enable/disable presolve

4

Not sure if this is a duplicate of #2171. HiGHS produces different results for [seed.mps.txt](https://github.com/user-attachments/files/18739298/seed.mps.txt) with `--presolve on` and `off`. Solver: highs --presolve on Status: Optimal Objective: -26760.686634486985 x0 =...

HiGHS generates a different result from other solvers

4

HiGHS returns different results from gurobi, scip and GLPK on [seed.mps.txt](https://github.com/user-attachments/files/18780232/seed.mps.txt), but actually is the same as the answer of CBC. Solver: HiGHS, CBC Status: Optimal Objective: 2363.670185116735 x0 =...

HiGHS crashes with `--presolve on` and `mip_rel_gap=0`

1

HiGHS crashes on [seed.mps.txt](https://github.com/user-attachments/files/18765205/seed.mps.txt) when `--presolve on` and `mip_rel_gap` is set to 0 at the same time (set `mip_abs_gap=0` would not trigger the crash). Not sure if this is a...

HiGHS crashes with presolve enabled

1

HiGHS (build from branch `latest` with assertions enabled) crashes with assertion failed when solving [seed.mps.txt](https://github.com/user-attachments/files/18740904/seed.mps.txt) in default mode or setting `--presolve on` ``` root@b9f8d0525121:/tmp/fuzz-mip# /usr/local/bin/highs --model_file result-MIP-1739180497-20h/run-583/seed.mps Running HiGHS 1.9.0...

heur_alns.c:1379: void tryAdd2variableBuffer(SCIP *, SCIP_VAR *, double, SCIP_VAR **, double *, int *, unsigned int): Assertion `SCIPisFeasIntegral(scip, val) || ! SCIPvarIsIntegral(var)' failed.

4

[seed.lp.txt](https://github.com/user-attachments/files/20883275/seed.lp.txt) This instance trigger a crash in scip with parameters: ``` numerics/feastol = 1e-9 numerics/epsilon = 1e-9 numerics/sumepsilon = 1e-9 lp/scaling = 0 ``` The log: ``` $> scip -f...

scip crashes with heurExecAlns(SCIP *, SCIP_HEUR *, SCIP_HEURTIMING, unsigned int, SCIP_RESULT *): Assertion `FALSE' failed

3

For [seed.lp.txt](https://github.com/user-attachments/files/20076036/seed.lp.txt), scip crashes with the following parameters: ``` numerics/feastol = 1e-9 lp/scaling = 0 numerics/epsilon = 1e-9 numerics/sumepsilon = 1e-9 ``` Actually, `numerics/epsilon` and `numerics/sumepsilon` are not necessary to...

Incorrect solution from scip when `numerics/feastol = 1e-9`

3

For [seed.mps.txt](https://github.com/user-attachments/files/19697609/seed.mps.txt), scip produces the wrong answer of `4983.45..` when setting `numerics/feastol = 1e-9`, while the correct answer should be `4936.16..`. I am not sure if this is a duplicate...

scip generates inconsistent solutions with non-default parameters

1

For [seed.lp.txt](https://github.com/user-attachments/files/20262272/seed.lp.txt), scip can generate the correct answer (objective = `-43484..`) with `numerics/feastol = 1e-9` (or by default), BUT, if additionally setting `numerics/epsilon = 1e-9` and `numerics/sumepsilon = 1e-9` (to...