Error trying to use Gurobi with Python-MIP: "function/symbol 'GRBloadenv' not found in library (error 0x7f)"

Answered

Eduardo Bonfá Carlos

• December 03, 2024 21:31
• Edited

As I am trying to use Gurobi 12.0.0 with the lib Python-MIP, after installing both the lib and the solver in my computer, when I try to call the solver I am getting an error message.

My code:

from mip import *
import numpy as np
import gurobipy
model = Model(sense=MINIMIZE, solver_name='GUROBI')

And this is the error I am receiving:

 

AttributeError: function/symbol 'GRBloadenv' not found in library 'C:\gurobi1200\win64\bin\gurobi120.dll': error 0x7f

It's important to note that the dll correctly exists in the directory pointed above.

I have used the Python-MIP library with the CBC solver without issues, as well as the Gurobi solver with Pyomo. However, due to this error, I haven't been able to use Gurobi with Python-MIP.

What could be causing this issue, please?

Regards,
Eduardo

Related to

• Python

1

• 

  Riley Clement

  Gurobi Staff

  • December 04, 2024 00:04

  Hi Eduardo,

  Please see the following note regarding GRBloadenv in the v12 release notes:
  https://docs.gurobi.com/projects/optimizer/en/current/reference/releasenotes/knownbugs.html#missing-symbols-in-shared-library-libgurobi120

  Note that Python-MIP looks to be poorly maintained, with many pending pull requests.  I expect you will need to wait till we publish 12.0.1 next year.

  Kind Regards,
  Riley

   

  0
• 

  Riley Clement

  Gurobi Staff

  • December 04, 2024 03:21

  I've created a fork of Python-MIP in which I've implemented the necessary changes:
  https://github.com/venaturum/python-mip/tree/gurobi1200

  If you are installing with pip then you can use the following command:

  pip install git+https://github.com/venaturum/python-mip.git@gurobi1200

  If you are using a package manager other than pip then I suspect there will be a way to ask it to install a package directly from the branch of a repository, but you will have to investigate.

  Note: this is valid for Gurobi 12.0.0 only!  Once Gurobi 12.0.1 is released you should be able to resume using the current Python-MIP release.

  - Riley

  2
• 

  David Torres Sanchez

  Gurobi Staff

  • December 04, 2024 11:00

  Thanks Riley! I created python-mip#398 to track this.

  Cheers, 
  David

  1

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