# "UndefVarError: with\_optimizer not defined" using GLPK

**URL:** <https://discourse.julialang.org/t/undefvarerror-with-optimizer-not-defined-using-glpk/42220>\
**Category:** Optimization (Mathematical)\
**Tags:** jump\
**Created:** [June 29, 2020, 2:06am UTC](https://discourse.julialang.org/t/undefvarerror-with-optimizer-not-defined-using-glpk/42220 "2020-06-29T02:06:00Z")\
**Posts on this page:** 7\
**Page:** 1

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**Author:** ![Ernesto\_Diaz](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/ernesto_diaz/32/8289_2.png) [@Ernesto\_Diaz](https://discourse.julialang.org/u/Ernesto_Diaz)\
**Post date:** [June 29, 2020, 2:06am UTC](https://discourse.julialang.org/t/undefvarerror-with-optimizer-not-defined-using-glpk/42220/1 "2020-06-29T02:06:00Z")

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I have JuMP v.0.18.6 . I think the message “UndefVarError: with\_optimizer not defined” is showed because I need JuMP v.0.19, but when I wrote Pkg.update(“JuMP”) JuMP wasn´t update.

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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:** [June 29, 2020, 2:54am UTC](https://discourse.julialang.org/t/undefvarerror-with-optimizer-not-defined-using-glpk/42220/2 "2020-06-29T02:54:02Z")

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Try

```nohighlight
] add JuMP@0.21

```

You probably have an old package holding you pack.

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<div class="post-metadata">

**Author:** ![Ernesto\_Diaz](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/ernesto_diaz/32/8289_2.png) [@Ernesto\_Diaz](https://discourse.julialang.org/u/Ernesto_Diaz)\
**Post date:** [June 29, 2020, 3:03am UTC](https://discourse.julialang.org/t/undefvarerror-with-optimizer-not-defined-using-glpk/42220/3 "2020-06-29T03:03:16Z")

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(@v1.4) pkg\> add JuMP@0.21.3  
Resolving package versions…  
ERROR: Unsatisfiable requirements detected for package JuMP [4076af6c]:  
JuMP [4076af6c] log:  
├─possible versions are: [0.18.3-0.18.6, 0.19.0-0.19.2, 0.20.0-0.20.1, 0.21.0-0.21.3] or uninstalled  
├─restricted to versions 0.21.3 by an explicit requirement, leaving only versions 0.21.3  
└─restricted by compatibility requirements with JuMPeR [707a9f91] to versions: 0.18.5-0.18.6 — no versions left  
└─JuMPeR [707a9f91] log:  
├─possible versions are: 0.6.0 or uninstalled  
└─restricted to versions \* by an explicit requirement, leaving only versions 0.6.0

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<div class="post-metadata">

**Author:** ![Ernesto\_Diaz](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/ernesto_diaz/32/8289_2.png) [@Ernesto\_Diaz](https://discourse.julialang.org/u/Ernesto_Diaz)\
**Post date:** [June 29, 2020, 3:04am UTC](https://discourse.julialang.org/t/undefvarerror-with-optimizer-not-defined-using-glpk/42220/4 "2020-06-29T03:04:09Z")

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(@v1.4) pkg\> add JuMP@0.21  
Updating registry at `C:\Users\Ernesto\.julia\registries\General`  
Updating git-repo `https://github.com/JuliaRegistries/General.git`  
Resolving package versions…  
ERROR: Unsatisfiable requirements detected for package JuMP [4076af6c]:  
JuMP [4076af6c] log:  
├─possible versions are: [0.18.3-0.18.6, 0.19.0-0.19.2, 0.20.0-0.20.1, 0.21.0-0.21.3] or uninstalled  
├─restricted to versions 0.21 by an explicit requirement, leaving only versions 0.21.0-0.21.3  
└─restricted by compatibility requirements with JuMPeR [707a9f91] to versions: 0.18.5-0.18.6 — no versions left  
└─JuMPeR [707a9f91] log:  
├─possible versions are: 0.6.0 or uninstalled  
└─restricted to versions \* by an explicit requirement, leaving only versions 0.6.0

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<div class="post-metadata">

**Author:** ![Ernesto\_Diaz](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/ernesto_diaz/32/8289_2.png) [@Ernesto\_Diaz](https://discourse.julialang.org/u/Ernesto_Diaz)\
**Post date:** [June 29, 2020, 3:14am UTC](https://discourse.julialang.org/t/undefvarerror-with-optimizer-not-defined-using-glpk/42220/5 "2020-06-29T03:14:26Z")

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Thanks, but the problem wasn´t resolved

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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:** [June 29, 2020, 3:27am UTC](https://discourse.julialang.org/t/undefvarerror-with-optimizer-not-defined-using-glpk/42220/6 "2020-06-29T03:27:11Z")

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You cannot use JuMPeR with the new version of JuMP.

To upgrade to the latest JuMP, you will need to remove it via `] rm JuMPeR`.

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<div class="post-metadata">

**Author:** ![Ernesto\_Diaz](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/ernesto_diaz/32/8289_2.png) [@Ernesto\_Diaz](https://discourse.julialang.org/u/Ernesto_Diaz)\
**Post date:** [June 29, 2020, 3:35am UTC](https://discourse.julialang.org/t/undefvarerror-with-optimizer-not-defined-using-glpk/42220/7 "2020-06-29T03:35:29Z")

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Thank you, very much. Problem solved