.to_preferred() gives "Windows fatal exception: access violation"

[YagoMasip]

Hello,

When executing this code:

from pint import UnitRegistry

ureg = UnitRegistry(system="SI",
                    autoconvert_offset_to_baseunit=True,
                    auto_reduce_dimensions=True,
                    autoconvert_to_preferred=True)

preferred_units = [ureg.pa, ureg.kelvin]    
ureg.default_preferred_units = preferred_units
print(1*ureg.atm)
print((1*ureg.atm).to_preferred())

I'm getting the following output in the Spyder console:

Windows fatal exception: access violation

Main thread:
Current thread 0x00001ed0 (most recent call first):
Windows fatal exception: access violation

Restarting kernel...

No ouput at all when executed in the Windows terminal.

I'm using:

Python 3.12.3 (tags/v3.12.3:f6650f9, Apr 9 2024, 14:05:25) [MSC v.1938 64 bit (AMD64)]
Pint 0.24.4

Thank you in advance,.

YagoMasip

[andrewgsavage]

what version of mip do you have installed?

[YagoMasip]

version 1.14.2,

I have just upgraded to 1.15.0 and the issue persists

[andrewgsavage]

I think it's related to this:

coin-or/python-mip#385

try using lower versions of mip, if you get it working please post the version

[YagoMasip]

Checked up to version 1.3.1 the issue with the access violation appears

Previous versions up to 1.3.0 there is no acces violation but other errors are shown, for example this one with version 1.3.0

 File c:\users\yagom\onedrive\documentos\python scripts\01 vle\vle\units.py:23
    print((1*ureg.atm).to_preferred())

  File ~\AppData\Local\Programs\Python\Python312\Lib\site-packages\pint\facets\plain\qto.py:190 in to_preferred
    units = _get_preferred(quantity, preferred_units)

  File ~\AppData\Local\Programs\Python\Python312\Lib\site-packages\pint\facets\plain\qto.py:336 in _get_preferred
    model = mip_Model()

  File ~\AppData\Local\Programs\Python\Python312\Lib\site-packages\mip\model.py:485 in __init__
    from mip import gurobi

  File ~\AppData\Local\Programs\Python\Python312\Lib\site-packages\mip\gurobi.py:264
    class SolverGurobi(Solver):

  File ~\AppData\Local\Programs\Python\Python312\Lib\site-packages\mip\gurobi.py:267 in SolverGurobi
    ffi.NULL):

NameError: name 'ffi' is not defined

[andrewgsavage]

coin-or/python-mip#384
it does not work on python 3.12 onwards

[YagoMasip]

Thank you, I understand the problem is in mip not in pint.

[YagoMasip]

I have just tried also:

pip install git+https://github.com/coin-or/python-mip.git as sugested in coin-or/python-mip#384 whith also no success.