# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1873

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

**Page:** 1874

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## [Differentiating through a Jump Problem](https://discourse.julialang.org/t/differentiating-through-a-jump-problem/31496)

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**Author:** [@DR59](https://discourse.julialang.org/u/DR59)\
**Replies:** 28\
**Last updated:** [November 28, 2019, 12:41am UTC](https://discourse.julialang.org/t/differentiating-through-a-jump-problem/31496 "2019-11-28T00:41:57Z")

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Hi all, I’m thinking about Gillespie simulations, as one might use to simulate the individual molecules of a chemical reaction. Clearly a Gillespie Simulation (JumpProblem) is non-differentiable, as it has non-determin…

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## [Eigenvectors from eigenvalues](https://discourse.julialang.org/t/eigenvectors-from-eigenvalues/31600)

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**Author:** [@jonniedie](https://discourse.julialang.org/u/jonniedie)\
**Replies:** 6\
**Last updated:** [November 28, 2019, 12:12am UTC](https://discourse.julialang.org/t/eigenvectors-from-eigenvalues/31600 "2019-11-28T00:12:09Z")

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Really neat paper. Seems pretty unbelievable that something this fundamental has gone unnoticed for so long. Eigenvectors from Eigenvalues

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## [Compile time slowdown from 1.1 to 1.2](https://discourse.julialang.org/t/compile-time-slowdown-from-1-1-to-1-2/27776)

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**Author:** [@Paul\_Soderlind](https://discourse.julialang.org/u/Paul_Soderlind)\
**Replies:** 12\
**Last updated:** [November 27, 2019, 10:59pm UTC](https://discourse.julialang.org/t/compile-time-slowdown-from-1-1-to-1-2/27776 "2019-11-27T22:59:27Z")

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I just tried to benchmark a suite of plots in 1.1.1 and then in 1.2.0 (Windows 64). It includes line plots, scatters, bars, contours and surfaces. (The underlying notebook is at JuliaTutorial/Tutorial\_04\_Plots.ipynb at …

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## [Type chains for multiple dispatch](https://discourse.julialang.org/t/type-chains-for-multiple-dispatch/31586)

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**Author:** [@atell\_soundtheory](https://discourse.julialang.org/u/atell_soundtheory)\
**Replies:** 3\
**Last updated:** [November 27, 2019, 8:55pm UTC](https://discourse.julialang.org/t/type-chains-for-multiple-dispatch/31586 "2019-11-27T20:55:33Z")

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Dear fellow Julians, I’m currently trying to design a package for computational differential geometry, and I’ve encountered a few places in my design where a certain enhancement of the dispatch semantics would be of gre…

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## [Ignoring missing data when plotting](https://discourse.julialang.org/t/ignoring-missing-data-when-plotting/14124)

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**Author:** [@Kryohi](https://discourse.julialang.org/u/Kryohi)\
**Replies:** 12\
**Last updated:** [November 27, 2019, 10:11pm UTC](https://discourse.julialang.org/t/ignoring-missing-data-when-plotting/14124 "2019-11-27T22:11:38Z")

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Kind of a newbie question, so if this isn’t the appropriate section I’ll move it. I was trying to plot a column of a dataframe with some elements that cannot be calculated. At first I thought of initialize them to 0, a…

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## [Cosine seems slow](https://discourse.julialang.org/t/cosine-seems-slow/31507)

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**Author:** [@sw72](https://discourse.julialang.org/u/sw72)\
**Replies:** 14\
**Last updated:** [November 27, 2019, 10:59am UTC](https://discourse.julialang.org/t/cosine-seems-slow/31507 "2019-11-27T10:59:28Z")

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I’m finding the cos function slow in Julia compared with Mathematica. For example: a = RandomReal\[NormalDistribution\[\], {2000, 2000}\]; RepeatedTiming\[b = Cos\[a\];\] {0.018, Null} function test() a=randn(2000,2000…

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## [Fail to call solvers from JuMP](https://discourse.julialang.org/t/fail-to-call-solvers-from-jump/31601)

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**Author:** [@Ksun46](https://discourse.julialang.org/u/Ksun46)\
**Replies:** 0\
**Last updated:** [November 27, 2019, 9:12pm UTC](https://discourse.julialang.org/t/fail-to-call-solvers-from-jump/31601 "2019-11-27T21:12:25Z")

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I was trying to use Ipopt from JuMP and got the following error julia\> using JuMP, Ipopt, Gurobi julia\> m = Model(with\_optimizer(Ipopt.Optimizer)) ERROR: MethodError: no method matching supports\_default\_copy\_to(::Ipopt…

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## [AmplNLWriter : supports\_constraint() is ambiguous in MathOptInterface](https://discourse.julialang.org/t/amplnlwriter-supports-constraint-is-ambiguous-in-mathoptinterface/31390)

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**Author:** [@dmit](https://discourse.julialang.org/u/dmit)\
**Replies:** 9\
**Last updated:** [November 27, 2019, 8:41pm UTC](https://discourse.julialang.org/t/amplnlwriter-supports-constraint-is-ambiguous-in-mathoptinterface/31390 "2019-11-27T20:41:43Z")

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Hi there you beautiful people! Complete Julia newbie here, so the problem I’m having may be trivial. I’m trying to use Couenne optimizer with AmplNLWriter interface, but can’t make it work. Here’s my hello-world level…

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## [Push! seems to be incorrect in this situation](https://discourse.julialang.org/t/push-seems-to-be-incorrect-in-this-situation/31589)

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**Author:** [@ke\_xu](https://discourse.julialang.org/u/ke_xu)\
**Replies:** 7\
**Last updated:** [November 27, 2019, 7:56pm UTC](https://discourse.julialang.org/t/push-seems-to-be-incorrect-in-this-situation/31589 "2019-11-27T19:56:43Z")

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function Append(vectorOfVector, vector) vector\[1\] = 0 push!(vectorOfVector,vector) vector\[1\] = 1 push!(vectorOfVector,vector) end vectorOfVectors = Vector{Vector{Int64}}() vector = Vector{Int64}(undef,1)…

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## [How to read NamedTtuples with JSON3?](https://discourse.julialang.org/t/how-to-read-namedttuples-with-json3/31597)

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**Author:** [@Elmer\_Cusipuma](https://discourse.julialang.org/u/Elmer_Cusipuma)\
**Replies:** 0\
**Last updated:** [November 27, 2019, 7:34pm UTC](https://discourse.julialang.org/t/how-to-read-namedttuples-with-json3/31597 "2019-11-27T19:34:16Z")

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I am trying to do the following using JSON3 struct data d::NamedTuple{(:a,:b,:c), Tuple{Symbol,T,T}} where T \<: Union{Nothing,Real} end JSON3.StructType(::Type{data}) = JSON3.Struct() But I get an error reading t…

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## [Customize Terminal Colors](https://discourse.julialang.org/t/customize-terminal-colors/31512)

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**Author:** [@Usor](https://discourse.julialang.org/u/Usor)\
**Replies:** 4\
**Last updated:** [November 27, 2019, 6:36pm UTC](https://discourse.julialang.org/t/customize-terminal-colors/31512 "2019-11-27T18:36:03Z")

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Is there an easy way to customize Julia terminal colors directly? For example, can you type something like setterminalcolors(default) or setterminalcolor(prompt, orange); setterminalcolor(juliakeywords, brown); # and …

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## [SystemError: mmap the operation completed successfully issue with SharedArrays](https://discourse.julialang.org/t/systemerror-mmap-the-operation-completed-successfully-issue-with-sharedarrays/31579)

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**Author:** [@jmcastro2109](https://discourse.julialang.org/u/jmcastro2109)\
**Replies:** 0\
**Last updated:** [November 27, 2019, 2:12pm UTC](https://discourse.julialang.org/t/systemerror-mmap-the-operation-completed-successfully-issue-with-sharedarrays/31579 "2019-11-27T14:12:19Z")

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I am confronting a very weird problem when parallelizing some function. The following MWE shows the problem using Distributed, SharedArrays rmprocs() addprocs() big\_array = rand(100,11,20000) function donothing(a) …

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## [Deactivate Shortcut Control D](https://discourse.julialang.org/t/deactivate-shortcut-control-d/31511)

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**Author:** [@Usor](https://discourse.julialang.org/u/Usor)\
**Replies:** 7\
**Last updated:** [November 27, 2019, 6:18pm UTC](https://discourse.julialang.org/t/deactivate-shortcut-control-d/31511 "2019-11-27T18:18:48Z")

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Is there a quick convenient way to disable the shortcut Control D (used to quit)?

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## [Problem installing JuliaPro on Linux Mint 19.1](https://discourse.julialang.org/t/problem-installing-juliapro-on-linux-mint-19-1/31450)

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**Author:** [@sbihorel](https://discourse.julialang.org/u/sbihorel)\
**Replies:** 2\
**Last updated:** [November 27, 2019, 5:36pm UTC](https://discourse.julialang.org/t/problem-installing-juliapro-on-linux-mint-19-1/31450 "2019-11-27T17:36:54Z")

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Hi I am getting back to Julia after years of non-usage. I’ve tried to install JuliaPro on my Linux Mint 19.1 (ie, a flavor of Ubuntu 18.04) desktop using the following steps: Using root account: Created: sudo /usr/li…

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## [Quickest method to convert Vector of Strings to 3 Vectors of Floats](https://discourse.julialang.org/t/quickest-method-to-convert-vector-of-strings-to-3-vectors-of-floats/31522)

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**Author:** [@scelles](https://discourse.julialang.org/u/scelles)\
**Replies:** 2\
**Last updated:** [November 27, 2019, 4:48pm UTC](https://discourse.julialang.org/t/quickest-method-to-convert-vector-of-strings-to-3-vectors-of-floats/31522 "2019-11-27T16:48:32Z")

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Hello, I have a vector of String like a = \["0.309042 46.586349 111.4", "0.309042 46.586349 111.1", "0.309042 46.586349 111.3"\] and want to get 3 vectors of coordinates (longitude, latitude, altitude) (Float64) I did …

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## [Best way to get all substrings or numbers matching a regex](https://discourse.julialang.org/t/best-way-to-get-all-substrings-or-numbers-matching-a-regex/31571)

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**Author:** [@Maurice\_Diamantini](https://discourse.julialang.org/u/Maurice_Diamantini)\
**Replies:** 9\
**Last updated:** [November 27, 2019, 3:56pm UTC](https://discourse.julialang.org/t/best-way-to-get-all-substrings-or-numbers-matching-a-regex/31571 "2019-11-27T15:56:07Z")

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Bonjour, What is the best way for getting a String on Number Vector from a regex (like with the old matchall method)? pat = r"\[+-\]?\\d+\\.?\\d\*" txt = "aaa -1 bbb +2.2 ccc 123.456 ddd" # findall? ranges = findall(pat, tx…

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## [Variable Alias Analysis](https://discourse.julialang.org/t/variable-alias-analysis/31545)

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**Author:** [@Qiyamah](https://discourse.julialang.org/u/Qiyamah)\
**Replies:** 1\
**Last updated:** [November 27, 2019, 3:49pm UTC](https://discourse.julialang.org/t/variable-alias-analysis/31545 "2019-11-27T15:49:08Z")

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Hi, is there a way that I can perform an variable alias analysis on a piece of AST? Thanks

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## [Function with Array of Abstract types as arguments](https://discourse.julialang.org/t/function-with-array-of-abstract-types-as-arguments/31574)

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**Author:** [@HenriDeh](https://discourse.julialang.org/u/HenriDeh)\
**Replies:** 4\
**Last updated:** [November 27, 2019, 2:59pm UTC](https://discourse.julialang.org/t/function-with-array-of-abstract-types-as-arguments/31574 "2019-11-27T14:59:10Z")

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So, because julia\> Uniform{Float64} \<: Distribution true julia\> Array{Uniform{Float64},1} \<: Array{Distribution} false I cannot make a function like foo(a::Array{Distribution}) = nothing and call it with foo(\[Unifo…

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## [How to ignore terminated process in pmap with no retry](https://discourse.julialang.org/t/how-to-ignore-terminated-process-in-pmap-with-no-retry/31578)

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**Author:** [@altre](https://discourse.julialang.org/u/altre)\
**Replies:** 0\
**Last updated:** [November 27, 2019, 1:58pm UTC](https://discourse.julialang.org/t/how-to-ignore-terminated-process-in-pmap-with-no-retry/31578 "2019-11-27T13:58:08Z")

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When a worker process in pmap gets killed, the parent worker aborts with a ProcessExitedException. Is there any way to prevent this? Fault tolerant \`pmap\` when worker goes down shows that it works when you specify a retr…

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## [Mmap problem with SharedArrays](https://discourse.julialang.org/t/mmap-problem-with-sharedarrays/31552)

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**Author:** [@jmcastro2109](https://discourse.julialang.org/u/jmcastro2109)\
**Replies:** 2\
**Last updated:** [November 27, 2019, 1:44pm UTC](https://discourse.julialang.org/t/mmap-problem-with-sharedarrays/31552 "2019-11-27T13:44:49Z")

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Hello, I am confronting a very weird problem when parallelizing some function. I understand that I am supposed to post a MWE but I could not recreate the issue in a simple problem. @everywhere function simulSample(Profi…

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## [First alpha release of JuMP 0.19 (JuMP/MathOptInterface)](https://discourse.julialang.org/t/first-alpha-release-of-jump-0-19-jump-mathoptinterface/16099)

<div class="topic-metadata">

**Author:** [@miles.lubin](https://discourse.julialang.org/u/miles.lubin)\
**Replies:** 12\
**Last updated:** [November 27, 2019, 1:40pm UTC](https://discourse.julialang.org/t/first-alpha-release-of-jump-0-19-jump-mathoptinterface/16099 "2019-11-27T13:40:58Z")

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To help out early adopters in the big transition to JuMP/MathOptInterface, we’ll be making development tags of JuMP master up to the JuMP 0.19 release. The first development release, v0.19-alpha is now tagged. This is th…

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## [What do I get when I subtype GPUArray?](https://discourse.julialang.org/t/what-do-i-get-when-i-subtype-gpuarray/31537)

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**Author:** [@jpsamaroo](https://discourse.julialang.org/u/jpsamaroo)\
**Replies:** 7\
**Last updated:** [November 27, 2019, 11:04am UTC](https://discourse.julialang.org/t/what-do-i-get-when-i-subtype-gpuarray/31537 "2019-11-27T11:04:44Z")

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As the main developer of ROCArrays.jl, I’m trying to understand what benefits I get when I make ROCArray \<: GPUArray. GPUArrays.jl is a rather large package (likely due to it also implementing JLArray), so it’s hard for …

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## [Recompiling stale cache files](https://discourse.julialang.org/t/recompiling-stale-cache-files/19381)

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**Author:** [@maximilianpreisinger](https://discourse.julialang.org/u/maximilianpreisinger)\
**Replies:** 15\
**Last updated:** [November 27, 2019, 11:00am UTC](https://discourse.julialang.org/t/recompiling-stale-cache-files/19381 "2019-11-27T11:00:16Z")

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Hello dear Julia users! I really like this language due to its speed and usability. However, a lot of times my modules are recompiling, which can take a long time when my script is starting. I read here and there some s…

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## [Multithreading and rand within a specific range](https://discourse.julialang.org/t/multithreading-and-rand-within-a-specific-range/31567)

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**Author:** [@HelgavonLichtenstein](https://discourse.julialang.org/u/HelgavonLichtenstein)\
**Replies:** 5\
**Last updated:** [November 27, 2019, 10:17am UTC](https://discourse.julialang.org/t/multithreading-and-rand-within-a-specific-range/31567 "2019-11-27T10:17:28Z")

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Hello, I am trying to find parameters that make my model work using brute force. To do this I need to run my model many times varying the parameters each time. It works when I do it without multithreading but I want to …

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## [Multithreading and for loops](https://discourse.julialang.org/t/multithreading-and-for-loops/31565)

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**Author:** [@StevenSiew](https://discourse.julialang.org/u/StevenSiew)\
**Replies:** 1\
**Last updated:** [November 27, 2019, 9:34am UTC](https://discourse.julialang.org/t/multithreading-and-for-loops/31565 "2019-11-27T09:34:45Z")

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Why does this works using Base.Threads A = zeros(3,3) Threads.@threads for col = 1:3 for row = 1:3 A\[row,col\]=(col-1)\*3+row end end display(A) But this does not work using Base.Threads A = zeros(3,…

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## [I'm unable to use assertion](https://discourse.julialang.org/t/im-unable-to-use-assertion/31563)

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**Author:** [@marouane1994](https://discourse.julialang.org/u/marouane1994)\
**Replies:** 5\
**Last updated:** [November 27, 2019, 8:55am UTC](https://discourse.julialang.org/t/im-unable-to-use-assertion/31563 "2019-11-27T08:55:21Z")

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An AssertionError raises in my code, when i want to assert count(!iszero,\[1 3;2 2\])to be equal to zero: @assert count(!iszero,\[1 3;2 2\])==0 but, everytime i do that the error occurs. Perhaps i can do: a= count(!iszero,…

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## [Codecov.submit() warning that coverage files do not exist in Travis CI](https://discourse.julialang.org/t/codecov-submit-warning-that-coverage-files-do-not-exist-in-travis-ci/31562)

<div class="topic-metadata">

**Author:** [@vlandau](https://discourse.julialang.org/u/vlandau)\
**Replies:** 2\
**Last updated:** [November 27, 2019, 7:50am UTC](https://discourse.julialang.org/t/codecov-submit-warning-that-coverage-files-do-not-exist-in-travis-ci/31562 "2019-11-27T07:50:56Z")

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Hi All, I have travis CI set up with my Julia package, and suddenly coverage files are not being found when trying to submit coverage reports to codecov. As a consequnce, a 0% coverage statistic is being submitted to Co…

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## [Can't update my package](https://discourse.julialang.org/t/cant-update-my-package/31536)

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**Author:** [@marouane](https://discourse.julialang.org/u/marouane)\
**Replies:** 2\
**Last updated:** [November 27, 2019, 7:45am UTC](https://discourse.julialang.org/t/cant-update-my-package/31536 "2019-11-27T07:45:50Z")

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i have this package on Github that i want to update after modifying simple things in it when i do (v1.2) pkg\> up QuantumRelayit starts to do the updationg operation but after a while it shows me the operation is timed ou…

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## [Registering/upgrading registered package \[Help Needed\]](https://discourse.julialang.org/t/registering-upgrading-registered-package-help-needed/31561)

<div class="topic-metadata">

**Author:** [@TsurHerman](https://discourse.julialang.org/u/TsurHerman)\
**Replies:** 1\
**Last updated:** [November 27, 2019, 7:39am UTC](https://discourse.julialang.org/t/registering-upgrading-registered-package-help-needed/31561 "2019-11-27T07:39:31Z")

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Help needed, I have a registered package written in 0.6 days, Signals, it uses REQUIRE instead of Project.toml. How do I upgrade it to \>1 ? do I simply commit the changes ( deleting REQUIRE putting in a proper Project.…

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## [Your friendly neighbourhood multithreaded Spiderman](https://discourse.julialang.org/t/your-friendly-neighbourhood-multithreaded-spiderman/31560)

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**Author:** [@StevenSiew](https://discourse.julialang.org/u/StevenSiew)\
**Replies:** 0\
**Last updated:** [November 27, 2019, 7:13am UTC](https://discourse.julialang.org/t/your-friendly-neighbourhood-multithreaded-spiderman/31560 "2019-11-27T07:13:49Z")

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Hi I am your friendly neighborhood multithreaded spiderman Today, you have gain a new superpower with your new suit called julia-1.3 Before you go swinging high above the building tops, I want to talk about thread safe…

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