# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1831

[Latest](https://discourse.julialang.org/latest.md) · [Categories](https://discourse.julialang.org/categories.md) · [Tags](https://discourse.julialang.org/tags.md)

**Page:** 1832

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## [Specifying StaticArray Types](https://discourse.julialang.org/t/specifying-staticarray-types/34204)

<div class="topic-metadata">

**Author:** [@scj](https://discourse.julialang.org/u/scj)\
**Replies:** 5\
**Last updated:** [February 5, 2020, 1:48pm UTC](https://discourse.julialang.org/t/specifying-staticarray-types/34204 "2020-02-05T13:48:44Z")

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If a struct’s field is a StaticArray, then how do I (generically) specify its type? As seen below, not specifying the type has an effect on performance, but my attempt is obviously no good either, as it’s far to specific…

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## [Run Parallel Python in Julia](https://discourse.julialang.org/t/run-parallel-python-in-julia/34201)

<div class="topic-metadata">

**Author:** [@Impressium](https://discourse.julialang.org/u/Impressium)\
**Replies:** 3\
**Last updated:** [February 5, 2020, 1:37pm UTC](https://discourse.julialang.org/t/run-parallel-python-in-julia/34201 "2020-02-05T13:37:12Z")

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How does PyCall work under the hood. Can I run parallel python processes within Julia?

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## [Suggestions for testing with dependencies from other languages](https://discourse.julialang.org/t/suggestions-for-testing-with-dependencies-from-other-languages/34207)

<div class="topic-metadata">

**Author:** [@DrChainsaw](https://discourse.julialang.org/u/DrChainsaw)\
**Replies:** 0\
**Last updated:** [February 5, 2020, 1:03pm UTC](https://discourse.julialang.org/t/suggestions-for-testing-with-dependencies-from-other-languages/34207 "2020-02-05T13:03:00Z")

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Hi, The tl;dr of this post is basically how much hassle it is to depend on pre-compiled c artifacts v.s. just using an existing python wrapper for said artifacts. I started the (perhaps foolish) endeavour to implement …

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## [How to set the zoomspeed for Camera3D in Makie.jl](https://discourse.julialang.org/t/how-to-set-the-zoomspeed-for-camera3d-in-makie-jl/34205)

<div class="topic-metadata">

**Author:** [@JesperMartinsson](https://discourse.julialang.org/u/JesperMartinsson)\
**Replies:** 0\
**Last updated:** [February 5, 2020, 11:58am UTC](https://discourse.julialang.org/t/how-to-set-the-zoomspeed-for-camera3d-in-makie-jl/34205 "2020-02-05T11:58:11Z")

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Is there a way to adjust the zoom speed (when scrolling the mouse) in Makie.jl and using a 3D camera? I can set the rotationspeed in 3D and zoomspeed in 2D but not zoomspeed in 3D. Thanks for a great package by the way!

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## [Memory allocation in generator with zip](https://discourse.julialang.org/t/memory-allocation-in-generator-with-zip/1903)

<div class="topic-metadata">

**Author:** [@gasagna](https://discourse.julialang.org/u/gasagna)\
**Replies:** 2\
**Last updated:** [February 5, 2020, 9:56am UTC](https://discourse.julialang.org/t/memory-allocation-in-generator-with-zip/1903 "2020-02-05T09:56:17Z")

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Hi, I am experiencing some suspect memory allocation using a generator containing a zip iterator. The minimal example is this: as = Vector{Float64}\[randn(5) for i = 1:200000\] bs = Vector{Float64}\[randn(5) for i = 1:200…

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## [Define sub-types or not?](https://discourse.julialang.org/t/define-sub-types-or-not/34183)

<div class="topic-metadata">

**Author:** [@mthelm85](https://discourse.julialang.org/u/mthelm85)\
**Replies:** 2\
**Last updated:** [February 5, 2020, 7:08am UTC](https://discourse.julialang.org/t/define-sub-types-or-not/34183 "2020-02-05T07:08:04Z")

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Consider the following contrived example: Suppose I wanted to implement my own custom Weight types and let’s say that some of them can be converted to standard units (pounds, kilograms, etc.) while others (for some stra…

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## [Debugging in CUDAnative](https://discourse.julialang.org/t/debugging-in-cudanative/34193)

<div class="topic-metadata">

**Author:** [@Michael\_Benton](https://discourse.julialang.org/u/Michael_Benton)\
**Replies:** 1\
**Last updated:** [February 5, 2020, 7:01am UTC](https://discourse.julialang.org/t/debugging-in-cudanative/34193 "2020-02-05T07:01:51Z")

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struggling to find the source of problems in some kernels I write due to I don’t know of a julia CUDA debugger, I’ve found some for C. I get: CUDA error: unspecified launch failure (code 719, ERROR\_LAUNCH\_FAILED) and …

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## [CuArray can't find libcuda](https://discourse.julialang.org/t/cuarray-cant-find-libcuda/34175)

<div class="topic-metadata">

**Author:** [@cuchxq](https://discourse.julialang.org/u/cuchxq)\
**Replies:** 10\
**Last updated:** [February 5, 2020, 6:59am UTC](https://discourse.julialang.org/t/cuarray-cant-find-libcuda/34175 "2020-02-05T06:59:33Z")

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I installed cuda10.2 on a ubuntu 18.10, and was able to build and run the some examples from the Cuda example folder, such as devicequery. But when I use Julia1.0.5LTS, and CuArray can’t find libcuda. and using JULIA\_D…

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## [Problem with curl.exe (Windows) and package installation](https://discourse.julialang.org/t/problem-with-curl-exe-windows-and-package-installation/29525)

<div class="topic-metadata">

**Author:** [@aerdely](https://discourse.julialang.org/u/aerdely)\
**Replies:** 61\
**Last updated:** [February 5, 2020, 4:22am UTC](https://discourse.julialang.org/t/problem-with-curl-exe-windows-and-package-installation/29525 "2020-02-05T04:22:57Z")

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With some packages I have tried to install, I get an error as follows: In another thread I have been told that probably my files curl.exe and/or powershell.exe are broken. I have checked and they seem to work fine. A…

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## [Semi-deep copy of array](https://discourse.julialang.org/t/semi-deep-copy-of-array/34135)

<div class="topic-metadata">

**Author:** [@Eben60](https://discourse.julialang.org/u/Eben60)\
**Replies:** 8\
**Last updated:** [February 4, 2020, 9:56pm UTC](https://discourse.julialang.org/t/semi-deep-copy-of-array/34135 "2020-02-04T21:56:16Z")

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I have defined a struct MyType and the corresponding method copy(a::MyType). Now I would like to have a method to copy an Array of MyType, applying this method to each element of the array. What is the proper Julian way…

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## [Efficient way to read large array from binary file in slices?](https://discourse.julialang.org/t/efficient-way-to-read-large-array-from-binary-file-in-slices/6847)

<div class="topic-metadata">

**Author:** [@tlnagy](https://discourse.julialang.org/u/tlnagy)\
**Replies:** 12\
**Last updated:** [February 4, 2020, 9:43pm UTC](https://discourse.julialang.org/t/efficient-way-to-read-large-array-from-binary-file-in-slices/6847 "2020-02-04T21:43:33Z")

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I’ve written a TIFF parser (GitHub - tlnagy/OMETIFF.jl: I/O operations for OME-TIFF files in Julia) and there are still some inefficiencies that I would like to fix. One problem is that I allocate a large array that wil…

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## [WeakKeyDict(x=\>x) holds on to memory](https://discourse.julialang.org/t/weakkeydict-x-x-holds-on-to-memory/34187)

<div class="topic-metadata">

**Author:** [@cstjean](https://discourse.julialang.org/u/cstjean)\
**Replies:** 1\
**Last updated:** [February 4, 2020, 9:39pm UTC](https://discourse.julialang.org/t/weakkeydict-x-x-holds-on-to-memory/34187 "2020-02-04T21:39:54Z")

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julia\> wk = let x = Ref{Any}(nothing) WeakKeyDict(x=\>x) end WeakKeyDict{Base.RefValue{Any},Base.RefValue{Any}} with 1 entry: RefValue{Any}(nothing) =\> RefValue{Any}(nothing) julia\> GC.gc() julia\> GC…

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## [\[RFC\] Julia at deRSE20](https://discourse.julialang.org/t/rfc-julia-at-derse20/34134)

<div class="topic-metadata">

**Author:** [@BeastyBlacksmith](https://discourse.julialang.org/u/BeastyBlacksmith)\
**Replies:** 6\
**Last updated:** [February 4, 2020, 9:07pm UTC](https://discourse.julialang.org/t/rfc-julia-at-derse20/34134 "2020-02-04T21:07:29Z")

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I just created a workshop idea for the conference of the german RSE association deRSE20 on their bazaar. I would be happy to find interested people to actually run the workshop ( since I don’t think I can do it by mysel…

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## [Non-admin installer for macOS?](https://discourse.julialang.org/t/non-admin-installer-for-macos/34185)

<div class="topic-metadata">

**Author:** [@curtosis](https://discourse.julialang.org/u/curtosis)\
**Replies:** 0\
**Last updated:** [February 4, 2020, 8:17pm UTC](https://discourse.julialang.org/t/non-admin-installer-for-macos/34185 "2020-02-04T20:17:23Z")

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Pretty much what it says on the tin… is there a way to install JuliaPro on macOS without needing administrator privileges?

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## [\[ANN\] Flux v0.10](https://discourse.julialang.org/t/ann-flux-v0-10/31660)

<div class="topic-metadata">

**Author:** [@dhairyagandhi96](https://discourse.julialang.org/u/dhairyagandhi96)\
**Replies:** 36\
**Last updated:** [February 4, 2020, 7:57pm UTC](https://discourse.julialang.org/t/ann-flux-v0-10/31660 "2020-02-04T19:57:14Z")

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We are delighted to announce the release of Flux v0.10. This is a huge release including the work of many contributors; the major development is that Flux now uses Zygote as its default backend for gradients, removing m…

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## [Can share Julia High Performance book](https://discourse.julialang.org/t/can-share-julia-high-performance-book/34178)

<div class="topic-metadata">

**Author:** [@johnh](https://discourse.julialang.org/u/johnh)\
**Replies:** 1\
**Last updated:** [February 4, 2020, 7:09pm UTC](https://discourse.julialang.org/t/can-share-julia-high-performance-book/34178 "2020-02-04T19:09:57Z")

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Somehow I have bought 3x copies of Julia High Performance - Second Edition by Avik Sengupta and Alan Edelman The Packt website shoudl allow me to share two copies if you already have a valid Packt subscripton. If you w…

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## [Slowdown \_after\_ package load](https://discourse.julialang.org/t/slowdown-after-package-load/33533)

<div class="topic-metadata">

**Author:** [@Peter\_Adelman](https://discourse.julialang.org/u/Peter_Adelman)\
**Replies:** 18\
**Last updated:** [February 4, 2020, 6:47pm UTC](https://discourse.julialang.org/t/slowdown-after-package-load/33533 "2020-02-04T18:47:30Z")

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I have a somewhat odd “my package is slow to load” problem that I cannot find another example of, because the most serious slowdown occurs after the package loads: julia\> using Dates julia\> now() 2020-01-18T19:22:19.392…

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## [Creating multiple variables with consecutive names using a for loop](https://discourse.julialang.org/t/creating-multiple-variables-with-consecutive-names-using-a-for-loop/34177)

<div class="topic-metadata">

**Author:** [@HoldenCaulfield](https://discourse.julialang.org/u/HoldenCaulfield)\
**Replies:** 8\
**Last updated:** [February 4, 2020, 6:09pm UTC](https://discourse.julialang.org/t/creating-multiple-variables-with-consecutive-names-using-a-for-loop/34177 "2020-02-04T18:09:14Z")

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I want to create several variables with consecutive names. For instance, I want to create 100 variables like variable\_1, variable\_2, … , variable\_100, and maybe assign a random vector to each of them, e.g. variable\_1 = r…

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## [Stop gradients from propagating through some branches of computation tree in Flux](https://discourse.julialang.org/t/stop-gradients-from-propagating-through-some-branches-of-computation-tree-in-flux/33392)

<div class="topic-metadata">

**Author:** [@e3c6](https://discourse.julialang.org/u/e3c6)\
**Replies:** 9\
**Last updated:** [February 4, 2020, 6:02pm UTC](https://discourse.julialang.org/t/stop-gradients-from-propagating-through-some-branches-of-computation-tree-in-flux/33392 "2020-02-04T18:02:24Z")

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Is it possible to perform some computation in my loss function that is excluded from the gradient, while still using the simple Flux.train! API? Tensorflow and Keras have something called stop\_gradient , which can be ap…

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## [How to garbage collect a DistributedArray for sure?](https://discourse.julialang.org/t/how-to-garbage-collect-a-distributedarray-for-sure/34174)

<div class="topic-metadata">

**Author:** [@Gregstrq](https://discourse.julialang.org/u/Gregstrq)\
**Replies:** 0\
**Last updated:** [February 4, 2020, 4:28pm UTC](https://discourse.julialang.org/t/how-to-garbage-collect-a-distributedarray-for-sure/34174 "2020-02-04T16:28:52Z")

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Let’s say I create a DistributedArray but then reassign the variable to a new one: using Distributed addprocs(1) using DistributedArrays, LinearAlgebra da = DArray(\[@spawnat wid LinearAlgebra.ones(div(1024^3, 8)) for …

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## [Warning for adding constraints: zero or small (\< 1e-13) coefficients, ignored](https://discourse.julialang.org/t/warning-for-adding-constraints-zero-or-small-1e-13-coefficients-ignored/34137)

<div class="topic-metadata">

**Author:** [@Arega\_Getaneh](https://discourse.julialang.org/u/Arega_Getaneh)\
**Replies:** 8\
**Last updated:** [February 4, 2020, 5:32pm UTC](https://discourse.julialang.org/t/warning-for-adding-constraints-zero-or-small-1e-13-coefficients-ignored/34137 "2020-02-04T17:32:31Z")

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I asked this question and it seems no one wants to help me: I am just using Gurobi 9.0 which solves non convex problems as well. I get this error: Warning for adding constraints: zero or small (\< 1e-13) coefficients, ig…

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## [Zygote: treating a model output as a constant](https://discourse.julialang.org/t/zygote-treating-a-model-output-as-a-constant/34172)

<div class="topic-metadata">

**Author:** [@HenriDeh](https://discourse.julialang.org/u/HenriDeh)\
**Replies:** 2\
**Last updated:** [February 4, 2020, 5:18pm UTC](https://discourse.julialang.org/t/zygote-treating-a-model-output-as-a-constant/34172 "2020-02-04T17:18:46Z")

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Say I have a model m = Dense(1,1), a function f(x) = x, and a loss(a,b,c) = m(a) - b - f(c). I don’t want zygote to differentiate on f(c) when calling gradient(() -\> loss(a,b,c), m) . How do I tell it that ? It is a pro…

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## [Circular reference crash when reading fasta file](https://discourse.julialang.org/t/circular-reference-crash-when-reading-fasta-file/34126)

<div class="topic-metadata">

**Author:** [@jonathanBieler](https://discourse.julialang.org/u/jonathanBieler)\
**Replies:** 1\
**Last updated:** [February 3, 2020, 4:18pm UTC](https://discourse.julialang.org/t/circular-reference-crash-when-reading-fasta-file/34126 "2020-02-03T16:18:41Z")

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I have this piece of code : function load\_genome(genome\_path, haschr=true) genome\_index = string(genome\_path,".fai") f = open(genome\_path) reader = BioSequences.FASTA.Reader(f; index=genome\_index) genom…

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## [Idea Julia Lite or 'Juliette'?](https://discourse.julialang.org/t/idea-julia-lite-or-juliette/34076)

<div class="topic-metadata">

**Author:** [@compleat](https://discourse.julialang.org/u/compleat)\
**Replies:** 154\
**Last updated:** [February 4, 2020, 3:33pm UTC](https://discourse.julialang.org/t/idea-julia-lite-or-juliette/34076 "2020-02-04T15:33:09Z")

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Hi. As I have taken on the learning of Julia as a project, I have increasingly wondered whether many of the ‘computer science niceties’ like immutability, strictness of variable types, broadcasting, etc, which undoubted…

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## [Parametric Type Usage](https://discourse.julialang.org/t/parametric-type-usage/34170)

<div class="topic-metadata">

**Author:** [@ohmsweetohm1](https://discourse.julialang.org/u/ohmsweetohm1)\
**Replies:** 1\
**Last updated:** [February 4, 2020, 3:25pm UTC](https://discourse.julialang.org/t/parametric-type-usage/34170 "2020-02-04T15:25:06Z")

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Suppose I have a type PieceWiseAffineFunction with a number of segments. I want to convert (approximate) an instante with m segments into an instant with n segments. (n\<m) type PieceWiseAffineFunction k::Vector{Flo…

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## [Different results for same model with DifferentialEquations.jl](https://discourse.julialang.org/t/different-results-for-same-model-with-differentialequations-jl/34155)

<div class="topic-metadata">

**Author:** [@moesphere](https://discourse.julialang.org/u/moesphere)\
**Replies:** 4\
**Last updated:** [February 4, 2020, 2:54pm UTC](https://discourse.julialang.org/t/different-results-for-same-model-with-differentialequations-jl/34155 "2020-02-04T14:54:52Z")

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I am defining two ODEProblems, where they are both the same but the implementation is different. There is a parameter I specify for one problem directly inside the function and for the other problem as an argument to the…

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## [DifferentialEquations + RecursiveArrayTools Broadcasting / CuArrays Kernel compilation error --](https://discourse.julialang.org/t/differentialequations-recursivearraytools-broadcasting-cuarrays-kernel-compilation-error/34132)

<div class="topic-metadata">

**Author:** [@cmarcotte](https://discourse.julialang.org/u/cmarcotte)\
**Replies:** 6\
**Last updated:** [February 4, 2020, 2:53pm UTC](https://discourse.julialang.org/t/differentialequations-recursivearraytools-broadcasting-cuarrays-kernel-compilation-error/34132 "2020-02-04T14:53:03Z")

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Hi, Finally have access to a CUDA capable GPU, so I’m trying to accelerate some finite-difference PDE solves using CuArrays and DifferentialEquations. I began with Chris’ simple reaction-diffusion demonstration here, a…

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## [Choosing a binary value with a certain probability (Biased random generator)](https://discourse.julialang.org/t/choosing-a-binary-value-with-a-certain-probability-biased-random-generator/34141)

<div class="topic-metadata">

**Author:** [@HoldenCaulfield](https://discourse.julialang.org/u/HoldenCaulfield)\
**Replies:** 4\
**Last updated:** [February 4, 2020, 2:46pm UTC](https://discourse.julialang.org/t/choosing-a-binary-value-with-a-certain-probability-biased-random-generator/34141 "2020-02-04T14:46:49Z")

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I want to determine a random binary variable according to its probability. So let’s say that I have a binary variable with a probability of 70%, so I want it to become 1 with the probability of 70% and zero with a probab…

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## [Error using PackageCompiler for Gadfly](https://discourse.julialang.org/t/error-using-packagecompiler-for-gadfly/31140)

<div class="topic-metadata">

**Author:** [@venuur](https://discourse.julialang.org/u/venuur)\
**Replies:** 7\
**Last updated:** [February 4, 2020, 12:48pm UTC](https://discourse.julialang.org/t/error-using-packagecompiler-for-gadfly/31140 "2020-02-04T12:48:23Z")

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Following the instructions here to build a system image with Gadfly: Home · Gadfly.jl I ran into a strange error saying PackageCompiler was not found despite having just run using PackageCompiler. Any idea how to troubl…

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## [JuMP precompiling error on an AWS EC2 Ubuntu server instance](https://discourse.julialang.org/t/jump-precompiling-error-on-an-aws-ec2-ubuntu-server-instance/33154)

<div class="topic-metadata">

**Author:** [@newstatement](https://discourse.julialang.org/u/newstatement)\
**Replies:** 15\
**Last updated:** [February 4, 2020, 11:12am UTC](https://discourse.julialang.org/t/jump-precompiling-error-on-an-aws-ec2-ubuntu-server-instance/33154 "2020-02-04T11:12:35Z")

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I am trying to use an AWS EC2 instance (t2.micro with Ubuntu Server 18.04) to run an optimization model designed in JuMP. I’m using Julia v1.3.1 and when I try to load JuMP package a fail occurs at precompiling. Some one…

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