# Latest

**URL:** https://discourse.julialang.org/latest.md?page=628

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

**Page:** 629

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## [Setting up a structure for a sequence of tests?](https://discourse.julialang.org/t/setting-up-a-structure-for-a-sequence-of-tests/102451)

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**Author:** [@frylock](https://discourse.julialang.org/u/frylock)\
**Replies:** 2\
**Last updated:** [August 3, 2023, 3:40pm UTC](https://discourse.julialang.org/t/setting-up-a-structure-for-a-sequence-of-tests/102451 "2023-08-03T15:40:36Z")

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EDIT: my issue was unrelated to the question - the problem wound up being improper spacing. I have a package that I’d like to have some tests built in for. There is a structure that wraps some functionality in a C++ lib…

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## [Minimisation of operator norm—solution does not match evaluated value \[Convex.jl\]](https://discourse.julialang.org/t/minimisation-of-operator-norm-solution-does-not-match-evaluated-value-convex-jl/102319)

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**Author:** [@not-fred](https://discourse.julialang.org/u/not-fred)\
**Replies:** 7\
**Last updated:** [August 3, 2023, 3:08pm UTC](https://discourse.julialang.org/t/minimisation-of-operator-norm-solution-does-not-match-evaluated-value-convex-jl/102319 "2023-08-03T15:08:22Z")

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I’m using Convex.jl to minimize the operator norm of a matrix (minimize opnorm(J,Inf)), but the solution (problem.optval) does not match the evaluated value after performing the optimisation (opnorm(evaluate(J,Inf))). A…

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## [Plots and GR\_jll is not working and fails to precompile](https://discourse.julialang.org/t/plots-and-gr-jll-is-not-working-and-fails-to-precompile/89657)

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**Author:** [@Engineering\_Science](https://discourse.julialang.org/u/Engineering_Science)\
**Replies:** 4\
**Last updated:** [August 3, 2023, 3:06pm UTC](https://discourse.julialang.org/t/plots-and-gr-jll-is-not-working-and-fails-to-precompile/89657 "2023-08-03T15:06:50Z")

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Hello I am trying to use julia for my Linear Algebra and Multivariable Calculus courses that requires plotting, however I cannot seem to get the package to work. I have read all the other plotting post as well as stack …

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## [Cannot Precompile Plots.jl due to GR](https://discourse.julialang.org/t/cannot-precompile-plots-jl-due-to-gr/88230)

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**Author:** [@SpinolaHours](https://discourse.julialang.org/u/SpinolaHours)\
**Replies:** 16\
**Last updated:** [August 3, 2023, 3:05pm UTC](https://discourse.julialang.org/t/cannot-precompile-plots-jl-due-to-gr/88230 "2023-08-03T15:05:25Z")

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Hi there, I recently upgraded to 1.8.0. At some point I lost the ability to precompile plots due to a GR\_jll error. I see other people have had similar issues and have tried the following with no luck: Removing .julia …

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## [How to Fix Failed to Precompile Plots: Required dependency Xorg\_xcb\_util\_jll \[2def613f-5ad1-5310-b15b-b15d46f528f5\] failed to load from a cache file](https://discourse.julialang.org/t/how-to-fix-failed-to-precompile-plots-required-dependency-xorg-xcb-util-jll-2def613f-5ad1-5310-b15b-b15d46f528f5-failed-to-load-from-a-cache-file/98909)

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**Author:** [@Freya\_the\_Goddess](https://discourse.julialang.org/u/Freya_the_Goddess)\
**Replies:** 3\
**Last updated:** [May 16, 2023, 9:05am UTC](https://discourse.julialang.org/t/how-to-fix-failed-to-precompile-plots-required-dependency-xorg-xcb-util-jll-2def613f-5ad1-5310-b15b-b15d46f528f5-failed-to-load-from-a-cache-file/98909 "2023-05-16T09:05:52Z")

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I add FresnelIntegrals yesterday and then suddenly Plots can’t be compiled. (can’t believe this FresnelIntegrals package can cause so many damages) I tried this but still not working: ERROR: The following 1 direct d…

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## [Code organization of a project with multiple simultaneously developed packages](https://discourse.julialang.org/t/code-organization-of-a-project-with-multiple-simultaneously-developed-packages/102447)

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**Author:** [@Neodym](https://discourse.julialang.org/u/Neodym)\
**Replies:** 1\
**Last updated:** [August 3, 2023, 2:59pm UTC](https://discourse.julialang.org/t/code-organization-of-a-project-with-multiple-simultaneously-developed-packages/102447 "2023-08-03T14:59:48Z")

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Hi, I’m developing a project that consists of multiple packages and some code that uses those packages. The packages will not be published in the Julia registry as it is a purely personal / learning project. Is there …

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## [AbstractDataFrame is not iterable, I just want to make a histogram](https://discourse.julialang.org/t/abstractdataframe-is-not-iterable-i-just-want-to-make-a-histogram/102391)

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**Author:** [@Axze-rgb](https://discourse.julialang.org/u/Axze-rgb)\
**Replies:** 8\
**Last updated:** [August 3, 2023, 1:01pm UTC](https://discourse.julialang.org/t/abstractdataframe-is-not-iterable-i-just-want-to-make-a-histogram/102391 "2023-08-03T13:01:35Z")

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Hello, why is it this is not iterable? Here is the code begin CairoMakie.activate!(type = “svg”) fig2 = Figure(pt\_per\_unit = 2) ax2 = Axis(fig\[1, 2\], xlabel = “MAPQ”) title2 = (“MAPQ of the hifi reads”) hist!(ax…

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## [Equivalent of Matlab's deval in DifferentialEquations.jl](https://discourse.julialang.org/t/equivalent-of-matlabs-deval-in-differentialequations-jl/102444)

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**Author:** [@jewh](https://discourse.julialang.org/u/jewh)\
**Replies:** 2\
**Last updated:** [August 3, 2023, 12:49pm UTC](https://discourse.julialang.org/t/equivalent-of-matlabs-deval-in-differentialequations-jl/102444 "2023-08-03T12:49:15Z")

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Is there a function like deval in DifferentialEquations.jl?

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## [Docstring linting (e.g., check for missing argument descriptions in the docstring)](https://discourse.julialang.org/t/docstring-linting-e-g-check-for-missing-argument-descriptions-in-the-docstring/102237)

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**Author:** [@abelsiqueira](https://discourse.julialang.org/u/abelsiqueira)\
**Replies:** 3\
**Last updated:** [August 3, 2023, 12:45pm UTC](https://discourse.julialang.org/t/docstring-linting-e-g-check-for-missing-argument-descriptions-in-the-docstring/102237 "2023-08-03T12:45:17Z")

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Is there a package for linting the docstrings? I am looking for something like pydocstyle, but something that just checks that the arguments in the function signature are included in the docstring is already valuable.

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## [Convex.jl constraints not enforced](https://discourse.julialang.org/t/convex-jl-constraints-not-enforced/102439)

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**Author:** [@UgeB](https://discourse.julialang.org/u/UgeB)\
**Replies:** 2\
**Last updated:** [August 3, 2023, 12:35pm UTC](https://discourse.julialang.org/t/convex-jl-constraints-not-enforced/102439 "2023-08-03T12:35:39Z")

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Hi, I am using Convex.jl to solve a simple least squares optimization problem with some monotonicity constraints on my variable \\phi. The least squares objective is minimized to zero which should not be the case as my …

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## [This month in Julia world - 2023-07](https://discourse.julialang.org/t/this-month-in-julia-world-2023-07/102276)

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**Author:** [@Krastanov](https://discourse.julialang.org/u/Krastanov)\
**Replies:** 6\
**Last updated:** [August 3, 2023, 12:04pm UTC](https://discourse.julialang.org/t/this-month-in-julia-world-2023-07/102276 "2023-08-03T12:04:49Z")

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A (seemingly?) monthly newsletter, mostly on julia internals, digestible for casual observers. A biased, incomplete, editorialized list of what I found interesting this month, with contributions from the community. “Int…

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## [Tracking occupied memory](https://discourse.julialang.org/t/tracking-occupied-memory/102442)

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**Author:** [@Jad\_Zeitouni](https://discourse.julialang.org/u/Jad_Zeitouni)\
**Replies:** 0\
**Last updated:** [August 3, 2023, 11:30am UTC](https://discourse.julialang.org/t/tracking-occupied-memory/102442 "2023-08-03T11:30:07Z")

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Is there any way to track occupied memory in Julia? Unfortunately I can’t provide a MWE but the code does something like this: struct State params::@NamedTuple begin ... # Bunch of vectors and matrices of Flo…

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## [Can we allow the syntax \`v.\[i\]\` to be converted to \`getindex.(v, i)\`?](https://discourse.julialang.org/t/can-we-allow-the-syntax-v-i-to-be-converted-to-getindex-v-i/102414)

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**Author:** [@Ronis\_BR](https://discourse.julialang.org/u/Ronis_BR)\
**Replies:** 10\
**Last updated:** [August 3, 2023, 11:03am UTC](https://discourse.julialang.org/t/can-we-allow-the-syntax-v-i-to-be-converted-to-getindex-v-i/102414 "2023-08-03T11:03:19Z")

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Hi! I have one scenario that happens all the time. I get a vector of vectors and I need to obtain each component individually to perform some analyses and plot the data. Today, I do: getindex.(v, 1) getindex.(v, 2) get…

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## [Why stringfy an array of UInt8s empties it?](https://discourse.julialang.org/t/why-stringfy-an-array-of-uint8s-empties-it/102389)

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**Author:** [@rocco\_sprmnt21](https://discourse.julialang.org/u/rocco_sprmnt21)\
**Replies:** 10\
**Last updated:** [August 3, 2023, 10:57am UTC](https://discourse.julialang.org/t/why-stringfy-an-array-of-uint8s-empties-it/102389 "2023-08-03T10:57:22Z")

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Is this result documented? What is the reason why v is emptied? julia\> v=\[0x41,0x42\] 2-element Vector{UInt8}: 0x41 0x42 julia\> String(v) "AB" julia\> v UInt8\[\] PS Is there a more efficient and side-effect free way…

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## [Best way to take trace of matrix product in Julia?](https://discourse.julialang.org/t/best-way-to-take-trace-of-matrix-product-in-julia/102380)

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**Author:** [@hshackle](https://discourse.julialang.org/u/hshackle)\
**Replies:** 17\
**Last updated:** [August 3, 2023, 10:55am UTC](https://discourse.julialang.org/t/best-way-to-take-trace-of-matrix-product-in-julia/102380 "2023-08-03T10:55:33Z")

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My question is essentially a rehash of the Python question posted here. Given two matrices A and B, I would like to compute the trace of A\*B, which does not require evaluating the full matrix multiplication. I’ve include…

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## [\[Seeking feedback\] Package for easy customization of startup.jl](https://discourse.julialang.org/t/seeking-feedback-package-for-easy-customization-of-startup-jl/102351)

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**Author:** [@abraemer](https://discourse.julialang.org/u/abraemer)\
**Replies:** 8\
**Last updated:** [August 3, 2023, 10:13am UTC](https://discourse.julialang.org/t/seeking-feedback-package-for-easy-customization-of-startup-jl/102351 "2023-08-03T10:13:13Z")

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Hi all, over in the other thread by @gdalle I suggested that his tutorials could include a small generator for startup.jl files with some common configurations like Revise.jl, OhMyREPL.jl, PkgTemplates.jl. He suggested …

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## [OrderedDict gives error in Mongoc.BSON()](https://discourse.julialang.org/t/ordereddict-gives-error-in-mongoc-bson/102437)

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**Author:** [@hansn](https://discourse.julialang.org/u/hansn)\
**Replies:** 0\
**Last updated:** [August 3, 2023, 9:01am UTC](https://discourse.julialang.org/t/ordereddict-gives-error-in-mongoc-bson/102437 "2023-08-03T09:01:10Z")

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I have the following code: lanprops = \[\] for lan in languages # NOTE: OrderedDict gives error in Mongoc.BSON() prop = OrderedDict{String, Any}() prop\["hasPropertyName"\] = "hasLabel" …

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## [Why HTTP.jl is not in Julia Core?](https://discourse.julialang.org/t/why-http-jl-is-not-in-julia-core/102426)

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**Author:** [@DeevsDeevs](https://discourse.julialang.org/u/DeevsDeevs)\
**Replies:** 5\
**Last updated:** [August 3, 2023, 9:01am UTC](https://discourse.julialang.org/t/why-http-jl-is-not-in-julia-core/102426 "2023-08-03T09:01:40Z")

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Hello Julia community, I have been using Julia for some time now and have found it to be an excellent language for various applications. However, I have noticed that HTTP.jl is not integrated into the Julia core, unlike…

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## [Nested struct as state variable in DifferentialEquations](https://discourse.julialang.org/t/nested-struct-as-state-variable-in-differentialequations/88583)

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**Author:** [@maxkapur](https://discourse.julialang.org/u/maxkapur)\
**Replies:** 7\
**Last updated:** [August 3, 2023, 8:53am UTC](https://discourse.julialang.org/t/nested-struct-as-state-variable-in-differentialequations/88583 "2023-08-03T08:53:41Z")

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I’m learning to use the DifferentialEquations ecosystem, and my goal is to simulate dynamic systems in which the state variable is a custom struct. In the simplest case, my state variable is just the x and y coordinates…

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## [CUFFT.plan\_fft! take a lot of memory, cannot be freed](https://discourse.julialang.org/t/cufft-plan-fft-take-a-lot-of-memory-cannot-be-freed/102377)

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**Author:** [@jinfreedom](https://discourse.julialang.org/u/jinfreedom)\
**Replies:** 3\
**Last updated:** [August 3, 2023, 8:03am UTC](https://discourse.julialang.org/t/cufft-plan-fft-take-a-lot-of-memory-cannot-be-freed/102377 "2023-08-03T08:03:06Z")

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Hi, I’m playing with CUDA.jl for FFT computations. I use CUFFT.plan\_fft! to perform in-place FFT on large complex arrays. What I found was the in-place plan itself seems to occupy a large chunk of GPU memory about the sa…

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## [Documentation explaining function supplied to \`count\` in Julia Docs?](https://discourse.julialang.org/t/documentation-explaining-function-supplied-to-count-in-julia-docs/102428)

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**Author:** [@bojohnson02](https://discourse.julialang.org/u/bojohnson02)\
**Replies:** 1\
**Last updated:** [August 3, 2023, 3:15am UTC](https://discourse.julialang.org/t/documentation-explaining-function-supplied-to-count-in-julia-docs/102428 "2023-08-03T03:15:46Z")

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I came across a particular function supplied to count in the documentation I wasn’t aware of previously. The \>(3) in count(\>(3), 1:7, init=0x03) is something I’ve been looking to replicate but didn’t know existed. Is the…

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## [JuliaSim - Simulating Reality (upcoming product by Julia Computing)](https://discourse.julialang.org/t/juliasim-simulating-reality-upcoming-product-by-julia-computing/58785)

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**Author:** [@ChrisRackauckas](https://discourse.julialang.org/u/ChrisRackauckas)\
**Replies:** 6\
**Last updated:** [August 2, 2023, 10:48pm UTC](https://discourse.julialang.org/t/juliasim-simulating-reality-upcoming-product-by-julia-computing/58785 "2023-08-02T22:48:56Z")

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JuliaSim: Simulating Reality Coming soon: JuliaSim is a next generation cloud-based simulation platform, combining the latest techniques in SciML with equation-based digital twin modeling and simulation. Surrogatize your…

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## [ClimatePlots installation](https://discourse.julialang.org/t/climateplots-installation/101609)

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**Author:** [@aasdelat](https://discourse.julialang.org/u/aasdelat)\
**Replies:** 2\
**Last updated:** [August 2, 2023, 9:27pm UTC](https://discourse.julialang.org/t/climateplots-installation/101609 "2023-08-02T21:27:05Z")

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I am not able to install the ClimatePlots package, due to a problem with the conda manager, that seems to not properly install matplotlib. I have completely uninstalled julia (executable and configuration-packages direc…

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## [Modeling constraints with CPLEXCP.jl](https://discourse.julialang.org/t/modeling-constraints-with-cplexcp-jl/102360)

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**Author:** [@Matheus\_Diogenes\_And](https://discourse.julialang.org/u/Matheus_Diogenes_And)\
**Replies:** 3\
**Last updated:** [August 2, 2023, 9:17pm UTC](https://discourse.julialang.org/t/modeling-constraints-with-cplexcp-jl/102360 "2023-08-02T21:17:47Z")

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Hello everyone. I am trying to model some constraints through constraint programming, by using CPLEXCP.jl. But I am having some issues with regards to translating the constraints into functions available by the library.…

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## [Nested array replacement](https://discourse.julialang.org/t/nested-array-replacement/102348)

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**Author:** [@Denis\_Ivanov](https://discourse.julialang.org/u/Denis_Ivanov)\
**Replies:** 4\
**Last updated:** [August 2, 2023, 8:40pm UTC](https://discourse.julialang.org/t/nested-array-replacement/102348 "2023-08-02T20:40:57Z")

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Hi! I would like to model this behavior on Julia: Substitution System So if we have rules ( 1 =\> \[\[1, 0\], \[1, 1\]\], 0 =\> \[\[0, 0\], \[0, 0\]\] ) and array \[\[1, 0\], \[1, 1\]\] than output should be \[1, 0, 0, 0\], \[1, 1, 0, 0\],…

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## [Debugging TSIT5 Internal Stage Steps](https://discourse.julialang.org/t/debugging-tsit5-internal-stage-steps/102416)

<div class="topic-metadata">

**Author:** [@yoshi](https://discourse.julialang.org/u/yoshi)\
**Replies:** 1\
**Last updated:** [August 2, 2023, 8:35pm UTC](https://discourse.julialang.org/t/debugging-tsit5-internal-stage-steps/102416 "2023-08-02T20:35:34Z")

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Is there an equivalent for step! that pauses after the computation of each internal stage of TSIT5?

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## [Is Pkg's dependency resolution order-dependent?](https://discourse.julialang.org/t/is-pkgs-dependency-resolution-order-dependent/30899)

<div class="topic-metadata">

**Author:** [@ffevotte](https://discourse.julialang.org/u/ffevotte)\
**Replies:** 3\
**Last updated:** [August 2, 2023, 8:33pm UTC](https://discourse.julialang.org/t/is-pkgs-dependency-resolution-order-dependent/30899 "2023-08-02T20:33:04Z")

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Here is an example where Pkg.adding first Cairo, then ImageView fails, whereas adding ImageView first works flawlessly. Is it expected that the dependency resolution depends on the order in which packages are added? In…

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## [Getting performance information from testsets](https://discourse.julialang.org/t/getting-performance-information-from-testsets/102417)

<div class="topic-metadata">

**Author:** [@jw3126](https://discourse.julialang.org/u/jw3126)\
**Replies:** 1\
**Last updated:** [August 2, 2023, 8:20pm UTC](https://discourse.julialang.org/t/getting-performance-information-from-testsets/102417 "2023-08-02T20:20:39Z")

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Testsets know already how much time they took to execute: using Test ts = @testset "outer" begin sleep(0.1) end # ts.time\_end - ts.time\_start = 0.10119009017944336 However, I would like to also know some other in…

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## [Get location and variable name from UndefVarError](https://discourse.julialang.org/t/get-location-and-variable-name-from-undefvarerror/102299)

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**Author:** [@t-anton](https://discourse.julialang.org/u/t-anton)\
**Replies:** 2\
**Last updated:** [August 2, 2023, 8:14pm UTC](https://discourse.julialang.org/t/get-location-and-variable-name-from-undefvarerror/102299 "2023-08-02T20:14:09Z")

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Hi All, How can I get an undefined variable name and its location? For example, in the code below x = a +1 The output is: UndefVarError: \`a\` not defined Stacktrace: \[1\] top-level scope @ In\[1\]:1 How do I get o…

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## [Undefined variable Error in a quote block](https://discourse.julialang.org/t/undefined-variable-error-in-a-quote-block/102404)

<div class="topic-metadata">

**Author:** [@shawn\_T](https://discourse.julialang.org/u/shawn_T)\
**Replies:** 1\
**Last updated:** [August 2, 2023, 8:09pm UTC](https://discourse.julialang.org/t/undefined-variable-error-in-a-quote-block/102404 "2023-08-02T20:09:33Z")

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Hi all, I was designing a macro and the code below is the return line of the macro, but it reports “i not defined”, I think it happens at $(result\[i\]) because once I replace it with other expr it is fine, so is there a …

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