SteadyCom doesn't works with Gurobi

[ggmirandac]

Hello,

I am working with reframed to model microbial communities, but the steadycom function doesn't works with the Gurobi solver.
Specifically, when the Gurobi solver is used, the following error is obtained:

AttributeError                            Traceback (most recent call last)
Cell In[16], [line 5](vscode-notebook-cell:?execution_count=16&line=5)
      1 comunidad = Community('arg_met', [darg, dlys])
      3 M9 = Environment.from_model(model)
----> [5](vscode-notebook-cell:?execution_count=16&line=5) solution = SteadyCom(comunidad, constraints=M9)

File /opt/homebrew/Caskroom/miniconda/base/envs/SaaLab/lib/python3.12/site-packages/reframed/community/SteadyCom.py:26, in SteadyCom(community, constraints, solver)
     22     solver = build_problem(community)
     24 objective = {community.merged_model.biomass_reaction: 1}
---> [26](https://file+.vscode-resource.vscode-cdn.net/opt/homebrew/Caskroom/miniconda/base/envs/SaaLab/lib/python3.12/site-packages/reframed/community/SteadyCom.py:26) sol = binary_search(solver, objective, minimize=False, constraints=constraints)
     28 solution = CommunitySolution(community, sol.values)
     29 solution.solver = solver

File /opt/homebrew/Caskroom/miniconda/base/envs/SaaLab/lib/python3.12/site-packages/reframed/community/SteadyCom.py:156, in binary_search(solver, objective, obj_frac, minimize, max_iters, abs_tol, constraints)
    153         fold = 0.5
    154     value = fold*diff + previous_value
--> [156](https://file+.vscode-resource.vscode-cdn.net/opt/homebrew/Caskroom/miniconda/base/envs/SaaLab/lib/python3.12/site-packages/reframed/community/SteadyCom.py:156) solver.update_growth(value)
    157 sol = solver.solve(objective, get_values=False, minimize=minimize, constraints=constraints)
    159 feasible = sol.status == Status.OPTIMAL

File /opt/homebrew/Caskroom/miniconda/base/envs/SaaLab/lib/python3.12/site-packages/reframed/community/SteadyCom.py:126, in build_problem.<locals>.update_growth(value)
    123 def update_growth(value):
    124     # TODO: find a solution that is not CPLEX specific
    125     coefficients = [(f"g_{x}", f"x_{x}", value) for x in community.organisms]
...
File src/gurobipy/_model.pyx:2105, in gurobipy._model.Model.getAttr()

File src/gurobipy/_attrutil.pyx:40, in gurobipy._attrutil._getattrinfo()

AttributeError: 'gurobipy.Model' object has no attribute 'linear_constraints'

The specific error that I found comes from AttributeError: 'gurobipy.Model' object has no attribute 'linear_constraints' which stems from the solver defined with Gurobi.

Bests,
Gabriel.