# Internals & Design

**URL:** https://discourse.julialang.org/c/dev/5.md?no_subcategories=false&page=55

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

**Page:** 56

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## [How can I handle SIGINT when using libjulia C API (in Python ctypes)?](https://discourse.julialang.org/t/how-can-i-handle-sigint-when-using-libjulia-c-api-in-python-ctypes/14794)

<div class="topic-metadata">

**Author:** [@tkf](https://discourse.julialang.org/u/tkf)\
**Replies:** 0\
**Last updated:** [September 11, 2018, 2:06am UTC](https://discourse.julialang.org/t/how-can-i-handle-sigint-when-using-libjulia-c-api-in-python-ctypes/14794 "2018-09-11T02:06:21Z")

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After I initialize libjulia by calling jl\_init\_with\_image, I found that libjulia takes over all SIGINT handlings. Is it correct? Is there any way for a host program (Python in my case) to handle the signals? I tried -…

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## [Eigen: the odd duck?](https://discourse.julialang.org/t/eigen-the-odd-duck/14451)

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**Author:** [@juthohaegeman](https://discourse.julialang.org/u/juthohaegeman)\
**Replies:** 19\
**Last updated:** [September 10, 2018, 3:32pm UTC](https://discourse.julialang.org/t/eigen-the-odd-duck/14451 "2018-09-10T15:32:51Z")

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I reiterate a question from PR27212 in the hope it has some more visibility here. I very much like the new interface of the matrix factorizations (or was it decompositions? :slight\_smile:) in julia 0.7/1.0 and all the …

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## [Adding file length as constraint to style guide](https://discourse.julialang.org/t/adding-file-length-as-constraint-to-style-guide/2005)

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**Author:** [@djsegal](https://discourse.julialang.org/u/djsegal)\
**Replies:** 35\
**Last updated:** [September 9, 2018, 2:24pm UTC](https://discourse.julialang.org/t/adding-file-length-as-constraint-to-style-guide/2005 "2018-09-09T14:24:33Z")

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I think most Julia packages are culprit to long file lengths. And as such, different cohesive blocks of logic are usually put into the same file Bugs hide in dirty code. And no open-source developer wants to touch an ug…

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## [We really need a CLI that hooks directly into Pkg](https://discourse.julialang.org/t/we-really-need-a-cli-that-hooks-directly-into-pkg/14639)

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**Author:** [@ExpandingMan](https://discourse.julialang.org/u/ExpandingMan)\
**Replies:** 16\
**Last updated:** [September 7, 2018, 5:45pm UTC](https://discourse.julialang.org/t/we-really-need-a-cli-that-hooks-directly-into-pkg/14639 "2018-09-07T17:45:33Z")

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Lately I’ve been looking into CI/CD with gitlab. This involves creating a bunch of setup yamls with bash commands much like in Travis. As I set these up I am always irked by having to do julia -e "import Pkg; Pkg.add(…

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## [Help implementing new iterate interface?](https://discourse.julialang.org/t/help-implementing-new-iterate-interface/14669)

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**Author:** [@crbinz](https://discourse.julialang.org/u/crbinz)\
**Replies:** 2\
**Last updated:** [September 7, 2018, 4:07pm UTC](https://discourse.julialang.org/t/help-implementing-new-iterate-interface/14669 "2018-09-07T16:07:28Z")

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I’m trying to implement the new iterate interface in JLD.jl, but I can’t get it to work, mostly because I don’t quite understand the original implementation. I tried Base.iterate(parent::Union{JldFile, JldGroup}, state…

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## [Method variable names and destructuring](https://discourse.julialang.org/t/method-variable-names-and-destructuring/14664)

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**Author:** [@Tamas\_Papp](https://discourse.julialang.org/u/Tamas_Papp)\
**Replies:** 1\
**Last updated:** [September 7, 2018, 3:03pm UTC](https://discourse.julialang.org/t/method-variable-names-and-destructuring/14664 "2018-09-07T15:03:20Z")

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I am trying to fix DocStringExtensions.jl/issues/67, for which I need to get the variable names also for destructured arguments. MWE: f((x, y), z) = x + y + z ## how to extract something like ((:x, :y), :z) ## from firs…

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## [Pkg offerings](https://discourse.julialang.org/t/pkg-offerings/14583)

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**Author:** [@iwelch](https://discourse.julialang.org/u/iwelch)\
**Replies:** 18\
**Last updated:** [September 6, 2018, 2:41pm UTC](https://discourse.julialang.org/t/pkg-offerings/14583 "2018-09-06T14:41:49Z")

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may I strongly suggest that the backend repository implement a system whereby it tries each submitted package on a vanilla julia 1.0 install, and if this submitted package fails with an error at pre-compilation time to t…

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## [Custom index arithmetic](https://discourse.julialang.org/t/custom-index-arithmetic/14374)

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**Author:** [@Tamas\_Papp](https://discourse.julialang.org/u/Tamas_Papp)\
**Replies:** 7\
**Last updated:** [September 6, 2018, 4:48am UTC](https://discourse.julialang.org/t/custom-index-arithmetic/14374 "2018-09-06T04:48:56Z")

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This is a clarifying question about custom indexing. If x::AbstractVector has a conforming interface, can I assume that that the valid indexes are firstindex(x):lastindex(x), ie they are integers (so nothing wacky li…

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## [Not sure how \`Adjoint\` types are described](https://discourse.julialang.org/t/not-sure-how-adjoint-types-are-described/14414)

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**Author:** [@dmbates](https://discourse.julialang.org/u/dmbates)\
**Replies:** 4\
**Last updated:** [September 5, 2018, 3:27pm UTC](https://discourse.julialang.org/t/not-sure-how-adjoint-types-are-described/14414 "2018-09-05T15:27:16Z")

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I am upgrading the MixedModels package to Julia v1.0 in the 0.7updates branch. This package uses linear algebra operations on various types of matrix-like objects. What would previously be a method for a generic like A…

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## [Pkg build fails needing to load dependencies](https://discourse.julialang.org/t/pkg-build-fails-needing-to-load-dependencies/14554)

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**Author:** [@bill-p](https://discourse.julialang.org/u/bill-p)\
**Replies:** 2\
**Last updated:** [September 5, 2018, 2:30pm UTC](https://discourse.julialang.org/t/pkg-build-fails-needing-to-load-dependencies/14554 "2018-09-05T14:30:43Z")

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I’m new to Julia, only one week experience. Tried to install the Gtk.jl package, but when I run build it finds missing dependencies, prompts for the admin password, lists the items it needs, but aborts at the system prom…

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## [Blog in documentation?](https://discourse.julialang.org/t/blog-in-documentation/14352)

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**Author:** [@DominiqueMakowski](https://discourse.julialang.org/u/DominiqueMakowski)\
**Replies:** 12\
**Last updated:** [September 1, 2018, 7:31am UTC](https://discourse.julialang.org/t/blog-in-documentation/14352 "2018-09-01T07:31:36Z")

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A blog is a good way to disseminate updates, examples or particular use-cases. They can be reposted, shared and so on. That’s why many packages (for instance for R) use their GitHub page for hosting a blog, and creating …

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## [Julia's history: array indexing](https://discourse.julialang.org/t/julias-history-array-indexing/14390)

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**Author:** [@00vareladavid](https://discourse.julialang.org/u/00vareladavid)\
**Replies:** 3\
**Last updated:** [September 1, 2018, 5:21am UTC](https://discourse.julialang.org/t/julias-history-array-indexing/14390 "2018-09-01T05:21:35Z")

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I just noticed that xs\[length(xs)+1+n:end\] returns an empty vector instead of throwing a bounds error. I think this is brilliant! When was this behavior introduced? I don’t think I’ve seen this behavior in other languag…

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## [Why doesn't Julia allow multiple inheritance?](https://discourse.julialang.org/t/why-doesnt-julia-allow-multiple-inheritance/14342)

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**Author:** [@lcmylin](https://discourse.julialang.org/u/lcmylin)\
**Replies:** 8\
**Last updated:** [August 31, 2018, 12:29pm UTC](https://discourse.julialang.org/t/why-doesnt-julia-allow-multiple-inheritance/14342 "2018-08-31T12:29:16Z")

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To be clear, when I write “multiple inheritance” in this context, I don’t mean multiple structural inheritance (as in C++), but rather multiple abstract class inheritance. In other words, the allowance for a node in the …

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## [Really Fast Hash Set and Map](https://discourse.julialang.org/t/really-fast-hash-set-and-map/14190)

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**Author:** [@nordlow](https://discourse.julialang.org/u/nordlow)\
**Replies:** 20\
**Last updated:** [August 29, 2018, 2:48pm UTC](https://discourse.julialang.org/t/really-fast-hash-set-and-map/14190 "2018-08-29T14:48:41Z")

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Does Julia have a fast generic implementation of hashed data structures, that is hash table and hash sets? Is the builtin Dict() as fast as in languages such as C++, Rust and D? Are there alternatives or examples of co…

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## [Embedding Julia into Java](https://discourse.julialang.org/t/embedding-julia-into-java/14048)

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**Author:** [@rssdev10](https://discourse.julialang.org/u/rssdev10)\
**Replies:** 2\
**Last updated:** [August 28, 2018, 11:44am UTC](https://discourse.julialang.org/t/embedding-julia-into-java/14048 "2018-08-28T11:44:48Z")

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Hello, I decided to check possibility of calling Julia code from Java and prepared some draft binding library - https://github.com/rssdev10/julia4j There are some simple but workable examples. First question - how to …

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## [Functionloc paths for the standard library](https://discourse.julialang.org/t/functionloc-paths-for-the-standard-library/14113)

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**Author:** [@Tamas\_Papp](https://discourse.julialang.org/u/Tamas_Papp)\
**Replies:** 1\
**Last updated:** [August 27, 2018, 8:30am UTC](https://discourse.julialang.org/t/functionloc-paths-for-the-standard-library/14113 "2018-08-27T08:30:57Z")

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While Base is correct, standard libraries seem to give the paths of the machine it was built in. Eg for the official 1.0 binaries, julia\> methods(Base.parent) # 9 methods for generic function "parent": \[1\] parent(V::Sub…

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## [Install attobot on a JuliaMath repo](https://discourse.julialang.org/t/install-attobot-on-a-juliamath-repo/14068)

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**Author:** [@waldyrious](https://discourse.julialang.org/u/waldyrious)\
**Replies:** 0\
**Last updated:** [August 26, 2018, 6:46am UTC](https://discourse.julialang.org/t/install-attobot-on-a-juliamath-repo/14068 "2018-08-26T06:46:27Z")

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I’ve just tried to set up attobot on JuliaMath/Tau.jl, but got the following message: You do not have permission to modify this app on JuliaMath. Please contact an Organization Owner. Can someone with owner access to…

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## [Is a more specialized element type of unique() a breaking change?](https://discourse.julialang.org/t/is-a-more-specialized-element-type-of-unique-a-breaking-change/14003)

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**Author:** [@laborg](https://discourse.julialang.org/u/laborg)\
**Replies:** 3\
**Last updated:** [August 25, 2018, 7:03am UTC](https://discourse.julialang.org/t/is-a-more-specialized-element-type-of-unique-a-breaking-change/14003 "2018-08-25T07:03:12Z")

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I’m working on https://github.com/JuliaLang/julia/pull/28737 to educate myself and have now come to a point where I’m wondering if a more specialized return type of the function unique would be a problem. Current behavi…

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## [Compile-time arithmetic for parameterized types](https://discourse.julialang.org/t/compile-time-arithmetic-for-parameterized-types/13991)

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**Author:** [@e3c6](https://discourse.julialang.org/u/e3c6)\
**Replies:** 1\
**Last updated:** [August 24, 2018, 12:36pm UTC](https://discourse.julialang.org/t/compile-time-arithmetic-for-parameterized-types/13991 "2018-08-24T12:36:44Z")

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I want to define type like this: struct A{L} x::NTuple{L,Int}; y::NTuple{L^2,Int} end Here L is known at compile-time. Therefore L^2 could also be known at compile-time in principle. But the example above is a syntax…

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## [Proposal: Add to Julia a macro to make operations between elements of structures easier](https://discourse.julialang.org/t/proposal-add-to-julia-a-macro-to-make-operations-between-elements-of-structures-easier/13837)

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**Author:** [@Ronis\_BR](https://discourse.julialang.org/u/Ronis_BR)\
**Replies:** 13\
**Last updated:** [August 21, 2018, 8:45pm UTC](https://discourse.julialang.org/t/proposal-add-to-julia-a-macro-to-make-operations-between-elements-of-structures-easier/13837 "2018-08-21T20:45:13Z")

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Hi guys, I would like to propose a macro to be added to Julia to make the operations between elements of structures easier. For example, let’s say you have a structure with lots of fields called Configurations. Like: s…

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## [Removal of workspace() and a way to clear variables](https://discourse.julialang.org/t/removal-of-workspace-and-a-way-to-clear-variables/11107)

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**Author:** [@digital\_carver](https://discourse.julialang.org/u/digital_carver)\
**Replies:** 12\
**Last updated:** [August 21, 2018, 5:41pm UTC](https://discourse.julialang.org/t/removal-of-workspace-and-a-way-to-clear-variables/11107 "2018-08-21T17:41:41Z")

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The removal of workspace() is a major change that seems to have been done without much discussion (Rationale for the removal of workspace()?, 25046, 10351, 22434). The suggested replacement, Revise.jl, might be good for…

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## [New Pkg: Immediate Compile and Version Variable?](https://discourse.julialang.org/t/new-pkg-immediate-compile-and-version-variable/13255)

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**Author:** [@iwelch](https://discourse.julialang.org/u/iwelch)\
**Replies:** 10\
**Last updated:** [August 21, 2018, 5:22pm UTC](https://discourse.julialang.org/t/new-pkg-immediate-compile-and-version-variable/13255 "2018-08-21T17:22:46Z")

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I am beginning to use Julia 1.0. Pkg.dir() no longer seems to work (and has no docs). What has replaced it? Pkg.status() works differently. Alas, these are just minor questions. I have a reason for posting to develo…

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## [Testing GC and finalizers](https://discourse.julialang.org/t/testing-gc-and-finalizers/13814)

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**Author:** [@lobingera](https://discourse.julialang.org/u/lobingera)\
**Replies:** 2\
**Last updated:** [August 21, 2018, 10:11am UTC](https://discourse.julialang.org/t/testing-gc-and-finalizers/13814 "2018-08-21T10:11:36Z")

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a) How is GC tested in Julia (read as: method)? b) Where could i find test code (read as: where in the julia repo)? c) Are there known tests for finalizers somewhere in packages?

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## [Pkg vs. shell REPL-mode](https://discourse.julialang.org/t/pkg-vs-shell-repl-mode/12688)

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**Author:** [@airpmb](https://discourse.julialang.org/u/airpmb)\
**Replies:** 3\
**Last updated:** [August 20, 2018, 6:36pm UTC](https://discourse.julialang.org/t/pkg-vs-shell-repl-mode/12688 "2018-08-20T18:36:51Z")

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I just noticed how the Pkg REPL-mode is “sticky” in the sense that after issuing a command in it you remain in Pkg mode, while the shell REPL-mode is not. I’m curious if the inconsistency is deliberate, and if so what th…

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## [Big overhead with the new lazy reshape/reinterpret](https://discourse.julialang.org/t/big-overhead-with-the-new-lazy-reshape-reinterpret/7635)

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**Author:** [@pablosanjose](https://discourse.julialang.org/u/pablosanjose)\
**Replies:** 35\
**Last updated:** [August 18, 2018, 9:02pm UTC](https://discourse.julialang.org/t/big-overhead-with-the-new-lazy-reshape-reinterpret/7635 "2018-08-18T21:02:19Z")

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I’m finding important performance regressions when indexing into the new reshape/reinterpret wrappers. (This is causing problems in trying to update NearestNeighbors.jl) Current v0.7 master julia\> using StaticArrays ju…

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## [Should modules no longer use \_\_precompile\_\_()?](https://discourse.julialang.org/t/should-modules-no-longer-use-precompile/13660)

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**Author:** [@galenlynch](https://discourse.julialang.org/u/galenlynch)\
**Replies:** 2\
**Last updated:** [August 18, 2018, 2:17pm UTC](https://discourse.julialang.org/t/should-modules-no-longer-use-precompile/13660 "2018-08-18T14:17:45Z")

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Reading the docs for 0.7, only \_\_precompile\_\_(false) is mentioned. It seems like modules are now precompiled be default, so is putting a \_\_precompile\_\_() statement at the top of a module still recommended?

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## [problems building julia 0.7 on Linux](https://discourse.julialang.org/t/problems-building-julia-0-7-on-linux/12221)

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**Author:** [@mywrathacademia](https://discourse.julialang.org/u/mywrathacademia)\
**Replies:** 3\
**Last updated:** [August 16, 2018, 12:31pm UTC](https://discourse.julialang.org/t/problems-building-julia-0-7-on-linux/12221 "2018-08-16T12:31:41Z")

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When I run make testall it fails at the cmdlineargs test. I have uninstalled julia and set FFLAGS=-ff2c but it still fails. My versioninfo() is: Julia Version 0.7.0-beta.182 Commit feaee9ebbc (2018-07-06 12:39 UTC) Plat…

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## [Build Julia with Cygwin64 on Windows 10, julia-debug.exe is missing?](https://discourse.julialang.org/t/build-julia-with-cygwin64-on-windows-10-julia-debug-exe-is-missing/13545)

<div class="topic-metadata">

**Author:** [@xiucai](https://discourse.julialang.org/u/xiucai)\
**Replies:** 2\
**Last updated:** [August 16, 2018, 10:34am UTC](https://discourse.julialang.org/t/build-julia-with-cygwin64-on-windows-10-julia-debug-exe-is-missing/13545 "2018-08-16T10:34:17Z")

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follow README.windows, on my magicbook (Intel Core i7-8550U), after almost 5 hours at least, done, BLAS and SuiteSparse cost most of time. but only julia.exe under usr/bin, where is juila-debug.exe? instructions are be…

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## [How to update badges on GitHub for different project](https://discourse.julialang.org/t/how-to-update-badges-on-github-for-different-project/13132)

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**Author:** [@affans](https://discourse.julialang.org/u/affans)\
**Replies:** 2\
**Last updated:** [August 15, 2018, 7:02pm UTC](https://discourse.julialang.org/t/how-to-update-badges-on-github-for-different-project/13132 "2018-08-15T19:02:06Z")

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I basically had to go through my projects using statements and see if packages were updated for 0.7/1.0 by looking at commits and activity. I noticed that for some packages, there are certain “badges” that tell you the …

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## [Where is OldPkg](https://discourse.julialang.org/t/where-is-oldpkg/13482)

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**Author:** [@galenlynch](https://discourse.julialang.org/u/galenlynch)\
**Replies:** 2\
**Last updated:** [August 15, 2018, 2:08pm UTC](https://discourse.julialang.org/t/where-is-oldpkg/13482 "2018-08-15T14:08:50Z")

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And/or what is its uuid? I see lots of traces of it being move around the internet but it’s not in stdlibs after I build and I can’t seem to find its repo or uuid.

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