# General Usage

**URL:** https://discourse.julialang.org/c/usage/6.md?page=26

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**Page:** 27

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## [How to use juliac.jl?](https://discourse.julialang.org/t/how-to-use-juliac-jl/123024)

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**Author:** [@MilesCranmer](https://discourse.julialang.org/u/MilesCranmer)\
**Replies:** 43\
**Last updated:** [December 6, 2025, 9:10pm UTC](https://discourse.julialang.org/t/how-to-use-juliac-jl/123024 "2025-12-06T21:10:50Z")

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I watched this talk on juliac which I am eager to try out but I can’t figure out how. I looked through the dev docs and the relevant PR, but no such luck, so am posting here. To get started I ran this: juliaup update n…

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## [Using Julia Compiled functions from Python with string arguments](https://discourse.julialang.org/t/using-julia-compiled-functions-from-python-with-string-arguments/134398)

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**Author:** [@Herve](https://discourse.julialang.org/u/Herve)\
**Replies:** 4\
**Last updated:** [December 6, 2025, 8:36pm UTC](https://discourse.julialang.org/t/using-julia-compiled-functions-from-python-with-string-arguments/134398 "2025-12-06T20:36:43Z")

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Hi I am experimenting with Julia code that I compile with juliac. I want to use it from Python (from various reasons, one being that it is the language of choice for many colleagues). One problem I stumbled upon is that…

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## [Reading a UTF-16-LE file](https://discourse.julialang.org/t/reading-a-utf-16-le-file/11687)

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**Author:** [@freeboson](https://discourse.julialang.org/u/freeboson)\
**Replies:** 5\
**Last updated:** [December 6, 2025, 5:58pm UTC](https://discourse.julialang.org/t/reading-a-utf-16-le-file/11687 "2025-12-06T17:58:28Z")

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I would like to read from a utf-16-le-encoded file. In this case, it’s a tsv. In python, I can read it as: import pandas as pd with open('file.tsv', encoding='utf-16-le') as f: df = pd.read\_table(f) In Julia, I th…

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## [PrecompileTools hangs](https://discourse.julialang.org/t/precompiletools-hangs/134397)

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**Author:** [@freeman](https://discourse.julialang.org/u/freeman)\
**Replies:** 0\
**Last updated:** [December 6, 2025, 1:46am UTC](https://discourse.julialang.org/t/precompiletools-hangs/134397 "2025-12-06T01:46:02Z")

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I use PrecompileTools everywhere I can. Some times the precompilation takes a very long time (think 10 minutes) in a way that’s unreasonable. I wait, and then when it eventually ends I get a long list of warnings with t…

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## [JuliaFormatter.jl set tab indent by default](https://discourse.julialang.org/t/juliaformatter-jl-set-tab-indent-by-default/87499)

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**Author:** [@monty](https://discourse.julialang.org/u/monty)\
**Replies:** 1\
**Last updated:** [December 6, 2025, 12:23am UTC](https://discourse.julialang.org/t/juliaformatter-jl-set-tab-indent-by-default/87499 "2025-12-06T00:23:56Z")

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How to force JuliaFormatter.jl to use tab indent by default? Thank you!

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## [\`Threads.atomic\_cas!\`, \`Threads.SpinLock\`, and \`@atomic\` documentation](https://discourse.julialang.org/t/threads-atomic-cas-threads-spinlock-and-atomic-documentation/134369)

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**Author:** [@Marco\_Lombardi](https://discourse.julialang.org/u/Marco_Lombardi)\
**Replies:** 2\
**Last updated:** [December 5, 2025, 2:16pm UTC](https://discourse.julialang.org/t/threads-atomic-cas-threads-spinlock-and-atomic-documentation/134369 "2025-12-05T14:16:55Z")

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Reading the Julia manual, I see that there is a “mild” deprecation for a series of atomic-related functions, including Threads.atomic\_cas!. I understand this is in favor of the @atomic macro, which is apparently more gra…

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## [Inconsistent behaviour of argmax](https://discourse.julialang.org/t/inconsistent-behaviour-of-argmax/134373)

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**Author:** [@jsjie](https://discourse.julialang.org/u/jsjie)\
**Replies:** 2\
**Last updated:** [December 5, 2025, 12:10pm UTC](https://discourse.julialang.org/t/inconsistent-behaviour-of-argmax/134373 "2025-12-05T12:10:25Z")

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An MWE: julia\> using Random julia\> a = rand(5, 5) 5×5 Matrix{Float64}: 0.304673 0.659002 0.223237 0.189379 0.735553 0.423152 0.844487 0.599046 0.60839 0.653539 0.808406 0.146324 0.866515 0.717432 0.3…

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## [World age delay doesn't occur with \`@eval\` in \`begin\` or \`let\` blocks, but does with \`eval\`](https://discourse.julialang.org/t/world-age-delay-doesnt-occur-with-eval-in-begin-or-let-blocks-but-does-with-eval/134367)

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**Author:** [@Benny](https://discourse.julialang.org/u/Benny)\
**Replies:** 6\
**Last updated:** [December 5, 2025, 9:58am UTC](https://discourse.julialang.org/t/world-age-delay-doesnt-occur-with-eval-in-begin-or-let-blocks-but-does-with-eval/134367 "2025-12-05T09:58:29Z")

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World age is expected to produce a delay between a method or Task’s compiled code and their changes to the global state, but it wasn’t clear to me what happens in top-level begin or let blocks. Weirdly, there’s this disc…

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## [Documenter build fails](https://discourse.julialang.org/t/documenter-build-fails/134287)

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**Author:** [@Magnus\_Lilledahl](https://discourse.julialang.org/u/Magnus_Lilledahl)\
**Replies:** 3\
**Last updated:** [December 5, 2025, 2:53am UTC](https://discourse.julialang.org/t/documenter-build-fails/134287 "2025-12-05T02:53:04Z")

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I am getting an error when I try to run a CI Job on GitLab using Documenter: ERROR: LoadError: ArgumentError: Package OpenSSL\_jll \[458c3c95-2e84-50aa-8efc-19380b2a3a95\] is required but does not seem to be installed: (I…

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## [Julia not respecting DEPOT\_PATH](https://discourse.julialang.org/t/julia-not-respecting-depot-path/134363)

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**Author:** [@Gattu\_Mytraya](https://discourse.julialang.org/u/Gattu_Mytraya)\
**Replies:** 2\
**Last updated:** [December 4, 2025, 10:44pm UTC](https://discourse.julialang.org/t/julia-not-respecting-depot-path/134363 "2025-12-04T22:44:41Z")

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Hi, I have been running into this problem for the last couple of days. I set the JULIA\_DEPOT\_PATH variable to a certain folder (on my university’s HPC). bash-4.4$ echo $JULIA\_DEPOT\_PATH/ /storage/work/mvg6042/.julia/ …

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## [Creating fully self-contained and pre-compiled library](https://discourse.julialang.org/t/creating-fully-self-contained-and-pre-compiled-library/131374)

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**Author:** [@asprionj](https://discourse.julialang.org/u/asprionj)\
**Replies:** 57\
**Last updated:** [December 4, 2025, 11:43am UTC](https://discourse.julialang.org/t/creating-fully-self-contained-and-pre-compiled-library/131374 "2025-12-04T11:43:38Z")

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Hi everyone. We intend to use julia to create a fully self-contained, completely pre-compiled library for integration in a larger software. I did read several posts, watched YouTube, etc. – there’s a lot but also quite s…

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## [\`Tuple\` of \`Union\` or \`Union\` of \`Tuple\`?](https://discourse.julialang.org/t/tuple-of-union-or-union-of-tuple/134311)

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**Author:** [@frankwswang](https://discourse.julialang.org/u/frankwswang)\
**Replies:** 8\
**Last updated:** [December 4, 2025, 10:28am UTC](https://discourse.julialang.org/t/tuple-of-union-or-union-of-tuple/134311 "2025-12-04T10:28:12Z")

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I want to annotate a type-unstable variable with a type-parameter constraint to improve the chance of union splitting during compilation. In general, should I do Tuple of Union or Union of Tuple? For example, which of t…

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## [Way to filter out #undef values from list?](https://discourse.julialang.org/t/way-to-filter-out-undef-values-from-list/14872)

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**Author:** [@djsegal](https://discourse.julialang.org/u/djsegal)\
**Replies:** 11\
**Last updated:** [December 4, 2025, 2:59am UTC](https://discourse.julialang.org/t/way-to-filter-out-undef-values-from-list/14872 "2025-12-04T02:59:27Z")

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For example, you have: \> x = Vector(4) 4-element Array{Any,1}: #undef #undef #undef #undef Now if you add some entries, you get: \> x\[2\] = 4 \> x\[4\] = 7 \> x 4-element Array{Any,1}: #undef 4 #undef 7 How…

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## [Interpolate over large HDF5 arrays](https://discourse.julialang.org/t/interpolate-over-large-hdf5-arrays/127079)

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**Author:** [@henry2004y](https://discourse.julialang.org/u/henry2004y)\
**Replies:** 18\
**Last updated:** [December 3, 2025, 5:52pm UTC](https://discourse.julialang.org/t/interpolate-over-large-hdf5-arrays/127079 "2025-12-03T17:52:48Z")

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Hi, I have a extremely large standard HDF5 file (2 TB) which saves a 3D array, let’s say B. With HDF5.jl, I can access individual elements of the array in the same way as this thread shows: load-hdf5-file-larger-than-me…

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## [Julia crashes when importing PyPlot](https://discourse.julialang.org/t/julia-crashes-when-importing-pyplot/134122)

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**Author:** [@Geometh](https://discourse.julialang.org/u/Geometh)\
**Replies:** 14\
**Last updated:** [December 3, 2025, 5:34pm UTC](https://discourse.julialang.org/t/julia-crashes-when-importing-pyplot/134122 "2025-12-03T17:34:24Z")

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Hi everyone, I decided to give my MacBookPro (13’’ 2019 Intel) a factory reset and now have a nice and clean set-up. Everything works fine, except importing PyPlot in Julia. Unfortunately, I don’t get any error message …

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## [How to test that a testset fails expectedly?](https://discourse.julialang.org/t/how-to-test-that-a-testset-fails-expectedly/134259)

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**Author:** [@jules](https://discourse.julialang.org/u/jules)\
**Replies:** 5\
**Last updated:** [December 3, 2025, 12:22pm UTC](https://discourse.julialang.org/t/how-to-test-that-a-testset-fails-expectedly/134259 "2025-12-03T12:22:03Z")

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Let’s say I have a package that defines a test macro. The macro creates some code that runs a @testset and inside a couple @tests. If I want to test that the macro works, I have to test that it succeeds if the conditions…

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## [Why is v1.12 "more prone to invalidations"?](https://discourse.julialang.org/t/why-is-v1-12-more-prone-to-invalidations/134327)

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**Author:** [@mattsignorelli](https://discourse.julialang.org/u/mattsignorelli)\
**Replies:** 0\
**Last updated:** [December 3, 2025, 12:15pm UTC](https://discourse.julialang.org/t/why-is-v1-12-more-prone-to-invalidations/134327 "2025-12-03T12:15:43Z")

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When v1.12.0 was first released some time ago, my precompile script immediately stopped being effective, even though my code was unchanged. In particular, it was ineffective if IJulia.jl was also loaded. The full details…

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## [HTTP has stopped working on api.eia.gov](https://discourse.julialang.org/t/http-has-stopped-working-on-api-eia-gov/134266)

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**Author:** [@wshobe](https://discourse.julialang.org/u/wshobe)\
**Replies:** 13\
**Last updated:** [December 3, 2025, 4:51am UTC](https://discourse.julialang.org/t/http-has-stopped-working-on-api-eia-gov/134266 "2025-12-03T04:51:23Z")

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All of a sudden, HTTP has stopped working to retrieve data from the api.eia.gov website. I have included a simple call that works in R and used to work in Julia but now times out no matter how much time I give it. In R, …

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## [Using \`CartesianIndex\` with Flux.jl](https://discourse.julialang.org/t/using-cartesianindex-with-flux-jl/134279)

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**Author:** [@Chrysoberyl](https://discourse.julialang.org/u/Chrysoberyl)\
**Replies:** 3\
**Last updated:** [December 3, 2025, 3:49am UTC](https://discourse.julialang.org/t/using-cartesianindex-with-flux-jl/134279 "2025-12-03T03:49:15Z")

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Is it possible to use CartesianIndex with Flux.jl within a Flux.with\_gradient block? Specifically I have a::Vector{Float32} and b::Vector{CartesianIndex}, and a\[b\] is in the gradient block. When I used this I got ERROR…

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## [How to define subcommands for a \`@main\` command in a Julia app?](https://discourse.julialang.org/t/how-to-define-subcommands-for-a-main-command-in-a-julia-app/134153)

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**Author:** [@singularitti](https://discourse.julialang.org/u/singularitti)\
**Replies:** 6\
**Last updated:** [December 2, 2025, 9:35pm UTC](https://discourse.julialang.org/t/how-to-define-subcommands-for-a-main-command-in-a-julia-app/134153 "2025-12-02T21:35:59Z")

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Since Julia now allows us to install an app/command to call it from the Shell by the @main function, I wonder how to mimic cases like some commands having subcommands in @main? Like git add, git status, git clone for git.…

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## [Makie scatter plot update issues](https://discourse.julialang.org/t/makie-scatter-plot-update-issues/134284)

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**Author:** [@Barabule](https://discourse.julialang.org/u/Barabule)\
**Replies:** 2\
**Last updated:** [December 2, 2025, 9:25pm UTC](https://discourse.julialang.org/t/makie-scatter-plot-update-issues/134284 "2025-12-02T21:25:42Z")

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Hi, I’m trying to make a GLMakie GUI with a draggable scatter plot. The dragging part works OK (it updated the positions), but when modifying the number of points plotted, the scatter plot only shows the initial number …

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## [Setting up corporate network proxy (with username and password)](https://discourse.julialang.org/t/setting-up-corporate-network-proxy-with-username-and-password/108903)

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**Author:** [@mobius-eng](https://discourse.julialang.org/u/mobius-eng)\
**Replies:** 2\
**Last updated:** [December 2, 2025, 3:23pm UTC](https://discourse.julialang.org/t/setting-up-corporate-network-proxy-with-username-and-password/108903 "2025-12-02T15:23:55Z")

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I am trying to set proxy settings for Julia to use, but without much success (I am behind corporate firewall). System: Windows 10, Julia 1.10 The proxy is set in the form http://\<User\>@\<Password\>@\<Addresss\>:\<Port\> (thi…

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## [Makie inspector labels don't work with rich text](https://discourse.julialang.org/t/makie-inspector-labels-dont-work-with-rich-text/134274)

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**Author:** [@AUK1939](https://discourse.julialang.org/u/AUK1939)\
**Replies:** 2\
**Last updated:** [December 2, 2025, 10:28am UTC](https://discourse.julialang.org/t/makie-inspector-labels-dont-work-with-rich-text/134274 "2025-12-02T10:28:48Z")

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The code below plots a simple bar chart. If I pass custom\_inspector\_label\_plain to barchart! everything works fine. But on GLMakie version v0.13.7 using rich text for inspector labels fails, see custom\_inspector\_label\_ri…

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## [REPL crashes upon completion](https://discourse.julialang.org/t/repl-crashes-upon-completion/134278)

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**Author:** [@zweiglimmergneis](https://discourse.julialang.org/u/zweiglimmergneis)\
**Replies:** 1\
**Last updated:** [December 2, 2025, 9:31am UTC](https://discourse.julialang.org/t/repl-crashes-upon-completion/134278 "2025-12-02T09:31:50Z")

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Create a struct, then define eltype for it, (see docs for the Iteration interface). Type Col in the REPL and press the TAB key, and the REPL will crash. This problem arises if eltype is defined. (full stacktrace). It oc…

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## [Understanding allocations when creating view of nested StructVector](https://discourse.julialang.org/t/understanding-allocations-when-creating-view-of-nested-structvector/134262)

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**Author:** [@disberd](https://discourse.julialang.org/u/disberd)\
**Replies:** 1\
**Last updated:** [December 2, 2025, 7:38am UTC](https://discourse.julialang.org/t/understanding-allocations-when-creating-view-of-nested-structvector/134262 "2025-12-02T07:38:35Z")

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Hi everyone, I am trying to wrap my head around why creating a view of a nested StructVector allocates or not depending on the number of fields in the eltype of the StructVector. Could you help me understand why this i…

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## [Amazon Linux 2023 Update (OpenSSL 3.2) causing OpenSSL.jl / HTTP.jl failures](https://discourse.julialang.org/t/amazon-linux-2023-update-openssl-3-2-causing-openssl-jl-http-jl-failures/134090)

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**Author:** [@Wikunia](https://discourse.julialang.org/u/Wikunia)\
**Replies:** 4\
**Last updated:** [December 1, 2025, 9:07pm UTC](https://discourse.julialang.org/t/amazon-linux-2023-update-openssl-3-2-causing-openssl-jl-http-jl-failures/134090 "2025-12-01T21:07:14Z")

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Hi everyone, I wanted to document a breaking issue that recently started appearing on AWS environments (specifically Amazon Linux 2023) as of mid-November 2025, in case anyone else is hitting a wall with their productio…

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## [Mystery failures when registering a package](https://discourse.julialang.org/t/mystery-failures-when-registering-a-package/134258)

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**Author:** [@loisel](https://discourse.julialang.org/u/loisel)\
**Replies:** 3\
**Last updated:** [December 1, 2025, 7:28pm UTC](https://discourse.julialang.org/t/mystery-failures-when-registering-a-package/134258 "2025-12-01T19:28:14Z")

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Hi, I’ve been having a mystery failure when registering a new version of MultiGridBarrier.jl. Note that this package was working until this new version, and it’s just the registration that’s failing. I can’t figure out …

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## [CairoMakie and Litterate: save images as separate files](https://discourse.julialang.org/t/cairomakie-and-litterate-save-images-as-separate-files/134180)

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**Author:** [@Alexander-Barth](https://discourse.julialang.org/u/Alexander-Barth)\
**Replies:** 2\
**Last updated:** [December 1, 2025, 11:44am UTC](https://discourse.julialang.org/t/cairomakie-and-litterate-save-images-as-separate-files/134180 "2025-12-01T11:44:32Z")

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In CairoMakie.jl v0.15.7 and Litterate.jl v2.21.0, images are now embedded (see below) per default, while previously they were stored as separate png files. Does somebody know to use separate files as before? Litterate …

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## [(very) Long compilation time when adding packages to Google Colab](https://discourse.julialang.org/t/very-long-compilation-time-when-adding-packages-to-google-colab/134166)

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**Author:** [@SGSGSG](https://discourse.julialang.org/u/SGSGSG)\
**Replies:** 3\
**Last updated:** [December 1, 2025, 10:39am UTC](https://discourse.julialang.org/t/very-long-compilation-time-when-adding-packages-to-google-colab/134166 "2025-12-01T10:39:16Z")

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I really enjoy Julia’s support on Google Colab! One annoying issue is that adding packages (even simple ones) leads to an endless (pre (?)-)compilation process. For instance: import Pkg; Pkg.add(\["Bootstrap"\]); still…

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## [Custom binary operators (with custom name)?](https://discourse.julialang.org/t/custom-binary-operators-with-custom-name/134141)

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**Author:** [@sylvaticus](https://discourse.julialang.org/u/sylvaticus)\
**Replies:** 9\
**Last updated:** [December 1, 2025, 5:42am UTC](https://discourse.julialang.org/t/custom-binary-operators-with-custom-name/134141 "2025-12-01T05:42:16Z")

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Aside +, \*, etc. is there a way to define my own binary operator, say Foo such that I can write something like: Foo(x,y) = \[some funny op using x and y\] ((x Foo b) Foo c) ....

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