Set cbc to default solver

[Crissal1995]

I've come across a bug; on Linux (but I think it's multi os) I installed only mip and, when launching my script using it, I got a NameError: name 'ffi' is not defined.
I searched where the problem was (line 264 of gurobi.py file, called in line 485 of model.py __init__), tried to fix it, but the problem was that in the first try except block ffi was initializated AFTER the raise of exception (going into the except block), causing the has_gurobi to be False and ffi to not exist in the workspace.
TL;DR setting the solver_name to cbc (the one that comes included with installation btw) there isn't any problem and everything works

[h-g-s]

Hi, are you using the last Python-MIP version (1.3) ? I think that in previous versions cffi was not included as a dependency, not it is and I think that installing it will also install cffi. Could you check it ?

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-- ============================================================= Haroldo Gambini Santos Computing Department Universidade Federal de Ouro Preto - UFOP email: haroldo@ufop.edu.br Haroldo.GambiniSantos@cs.kuleuven.be home/research page: www.decom.ufop.br/haroldo It has long been an axiom of mine that the little things are infinitely the most important. -- Sir Arthur Conan Doyle, "A Case of Identity"

On Mon, 17 Jun 2019, Cristiano wrote: I've come across a bug; on Linux (but I think it's multi os) I installed only mip and, when launching my script using it, I got a NameError: name 'ffi' is not defined. I searched where the problem was (line 264 of gurobi.py file, called in line 485 of model.py init), tried to fix it, but the problem was that in the first try except block ffi was initializated AFTER the raise of exception (going into the except block), causing the has_gurobi to be False and ffi to not exist in the workspace. TL;DR setting the solver_name to cbc (the one that comes included with installation btw) there isn't any problem and everything works _______________________________________________________________________________________________ You can view, comment on, or merge this pull request online at:   #2 Commit Summary * Set cbc to default solver File Changes * M mip/model.py (2) Patch Links: * https://github.com/coin-or/python-mip/pull/2.patch * https://github.com/coin-or/python-mip/pull/2.diff — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub, or mute thethread.[AB4VZOTUDQDJK5427A2NV4LP3BZQLA5CNFSM4HY4QSDKYY3PNVWWK3TUL52HS4DFUVEXG43VMWVGG33NNVSW45 C7NFSM4G2BOISQ.gif]

[tkralphs]

If you look at the fork, the parent commit to the PR is d88a1da, which is 1.3.

[Crissal1995]

Hi, are you using the last Python-MIP version (1.3) ? I think that in previous versions cffi was not included as a dependency, not it is and I think that installing it will also install cffi. Could you check it ?

Yes, I'm using the lastest MIP version.
I noticed that with my PR gurobi won't be ever selected (because solver_name is always equal to cbc), so instead I think it's better to raise an exception into gurobi.py in the except section (after has_gurobi = False)

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EDIT
By the way MIP is working great with Gurobi installed (mip will find and use gurobi), but this problem is showing with only mip installed

[h-g-s]

It was really a bug for detecting gurobi. I applied a version of your patch (without the formatting changes) and released 1.3.1. Thanks a lot for the fix.

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-- ============================================================= Haroldo Gambini Santos Computing Department Universidade Federal de Ouro Preto - UFOP email: haroldo@ufop.edu.br Haroldo.GambiniSantos@cs.kuleuven.be home/research page: www.decom.ufop.br/haroldo It has long been an axiom of mine that the little things are infinitely the most important. -- Sir Arthur Conan Doyle, "A Case of Identity"

On Tue, 18 Jun 2019, Cristiano wrote: Hi, are you using the last Python-MIP version (1.3) ? I think that in previous versions cffi was not included as a dependency, not it is and I think that installing it will also install cffi. Could you check it ? Yes, I'm using the lastest MIP version. I noticed that with my PR gurobi won't be ever selected (because solver_name is always equal to cbc), so instead I think it's better to raise an exception into gurobi.py in the except section (after has_gurobi = False) — You are receiving this because you commented. Reply to this email directly, view it on GitHub, or mute thethread.[AB4VZOVG6GQ2BFR47CO6KKDP3D2GXA5CNFSM4HY4QSDKYY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJK TDN5WW2ZLOORPWSZGODX65XTY.gif]

[Crissal1995]

You're welcome!