# Problem with CPLEX variable types using JuMP

**URL:** <https://discourse.julialang.org/t/problem-with-cplex-variable-types-using-jump/48415>\
**Category:** Optimization (Mathematical)\
**Tags:** question, jump\
**Created:** [October 15, 2020, 8:30am UTC](https://discourse.julialang.org/t/problem-with-cplex-variable-types-using-jump/48415 "2020-10-15T08:30:38Z")\
**Posts on this page:** 1\
**Showing post:** 6

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**Author:** ![odow](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/odow/32/28685_2.png) [@odow](https://discourse.julialang.org/u/odow)\
**Post date:** [October 15, 2020, 9:02pm UTC](https://discourse.julialang.org/t/problem-with-cplex-variable-types-using-jump/48415/6 "2020-10-15T21:02:30Z")

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Make sure you read the following before using `CPLEX#master`. It also explains when a new version will be tagged:

> [@\[ANN\] Upcoming breaking changes to CPLEX.jl and Gurobi.jl](https://discourse.julialang.org/t/ann-upcoming-breaking-changes-to-cplex-jl-and-gurobi-jl/47814):
>
> Update: 20 October 2020: New versions of CPLEX.jl and Gurobi.jl are tagged. tl;dr: CPLEX.jl and Gurobi.jl will have major breaking changes in the next latest release. If you just use CPLEX.Optimizer() or Gurobi.Optimizer() with JuMP, nothing changes. If you use any lower-level functionality in CPLEX.jl or Gurobi.jl (e.g., solver-dependent callbacks, or functions from the C API), your code will break. Furthermore, all support for MathProgBase has been removed. You can try out the changes by addi…

The underlying issue for this is complicated. I wasn’t aware `CPXPARAM_OptimalityTarget` changes the problem type, so I should add some better tests.

Edit: added a test so this doesn’t break in future: [Add test for CPXPARAM\_OptimalityTarget by odow · Pull Request #332 · jump-dev/CPLEX.jl · GitHub](https://github.com/jump-dev/CPLEX.jl/pull/332)

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