# Warm Starts in JuMP 0.21 & GLPK 0.12.1

**URL:** <https://discourse.julialang.org/t/warm-starts-in-jump-0-21-glpk-0-12-1/36223>\
**Category:** Optimization (Mathematical)\
**Tags:** question, package\
**Created:** [March 19, 2020, 7:49pm UTC](https://discourse.julialang.org/t/warm-starts-in-jump-0-21-glpk-0-12-1/36223 "2020-03-19T19:49:54Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![azberman](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/azberman/32/8213_2.png) [@azberman](https://discourse.julialang.org/u/azberman)\
**Post date:** [March 19, 2020, 7:49pm UTC](https://discourse.julialang.org/t/warm-starts-in-jump-0-21-glpk-0-12-1/36223/1 "2020-03-19T19:49:54Z")

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When I run a version of the code below, I receive the following error:

Warning: MathOptInterface.VariablePrimalStart() is not supported by MathOptInterface.Bridges.LazyBridgeOptimizer{GLPK.Optimizer}. This information will be discarded.

└ @ MathOptInterface.Utilities ~/.julia/packages/MathOptInterface/XiH8D/src/Utilities/copy.jl:140

```julia
using JuMP
using GLPK

    prev_u = .15
	model = Model(with_optimizer_attributes(GLPK.Optimizer))
	@variable(model, u >= 0.1, start = prev_u)
    optimize!(model)

```

What am I doing incorrectly?

---

<div class="post-metadata">

**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:** [March 19, 2020, 9:33pm UTC](https://discourse.julialang.org/t/warm-starts-in-jump-0-21-glpk-0-12-1/36223/2 "2020-03-19T21:33:17Z")

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GLPK does not support starting values. Neither does `Clp`. `Cbc` does though.