[electroly]

I don't know about everyone else, but slow Julia compilation continues to cause me ongoing suffering to this day. I don't think they're ever going to "fix" this. On a standard GitHub Actions Windows worker, installing the public Julia packages I use, precompiling, and compiling the sysimage takes over an hour. That's not an exaggeration. I had to juice the worker up to a custom 4x sized worker to get the wall clock time to something reasonable.

It took me days to get that build to work; doing this compilation once in CI so you don't have to do it on every machine is trickier than it sounds in Julia. The "obvious" way (install packages in Docker, run container on target machine) does not work because Julia wants to see exactly the same machine that it was precompiled on. It ends up precompiling again every time you run the container on other machines. I nearly shed a tear the first time I got Julia not to precompile everything again on a new machine.

R and Python are done in five minutes on the standard worker and it was easy; it's just the amount of time it takes to download and extract the prebuilt binaries. Do that inside a Docker container and it's portable as expected. I maintain Linux and Windows environments for the three languages and Julia causes me the most headaches, by far. I absolutely do not care about the tiny improvement in performance from compiling for my particular microarch; I would opt into prebuilt x86_64 generic binaries if Julia had them. I'm very happy to take R's and Python's prebuilt binaries.

[vchuravy]

I am very interested in improving the user-experience around precompilation and performance, may I ask why you are creating a sysimage from scratch?

> I would opt into prebuilt x86_64 generic binaries if Julia had them

The environment varial JULIA_CPU_TARGET [1] is what you are looking for, it controls what micro-architecture Julia emits for and supports multi-versioning.

As an example Julia is built with [2]: generic;sandybridge,-xsaveopt,clone_all;haswell,-rdrnd,base(1)

[1] https://docs.julialang.org/en/v1/manual/environment-variable...

[2] https://github.com/JuliaCI/julia-buildkite/blob/9c9f7d324c94...

[electroly]

I have a monorepo full of Julia analysis scripts written by different people. I want to run them in a Docker container on ephemeral Linux EC2 instances and on user Windows workstations. I don't want to sit through precompilation of all dependencies whenever a new machine runs a particular version of the Julia project for the first time because it takes a truly remarkable amount of time. For the ephemeral Linux instances running Julia in Docker, that happens on every run. Precompiling at Docker build time doesn't help you; it precompiles everything again when you run that container on a different host computer. R and Python don't work like this; if you install everything during the Docker image build, they will not suddenly trigger a lengthy recompilation when run on a different host machine.

I am intimately familiar with JULIA_CPU_TARGET; it's part of configuring PackageCompiler and I had to spend a fair amount of time figuring it out. Mine is [0]. It's not related to what I was discussing there. I am looking for Julia to operate a package manager service like R's CRAN/Posit PPM or Python's PyPI/Conda that distributes compiled binaries for supported platforms. JuliaHub only distributes source code.

[0] generic;skylake-avx512,clone_all;cascadelake,clone_all;icelake-server,clone_all;sapphirerapids,clone_all;znver4,clone_all;znver2,clone_all

[JanisErdmanis]

> It took me days to get that build to work; doing this compilation once in CI so you don't have to do it on every machine is trickier than it sounds in Julia

You may be interested in looking into AppBundler. Apart from the full application packaging it also offers ability to make Julia image bundles. While offering sysimage compilation option it also enables to bundle an application via compiled pkgimages which requires less RAM and is much faster to compile.