# Precompilation for almost every package that I use even though I used that package before

**URL:** <https://discourse.julialang.org/t/precompilation-for-almost-every-package-that-i-use-even-though-i-used-that-package-before/130265>\
**Category:** General Usage\
**Tags:** precompilation\
**Created:** [June 27, 2025, 1:22am UTC](https://discourse.julialang.org/t/precompilation-for-almost-every-package-that-i-use-even-though-i-used-that-package-before/130265 "2025-06-27T01:22:54Z")\
**Posts on this page:** 6\
**Page:** 1

<div class="post-metadata">

**Author:** ![Mend-Amar\_Badral](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/mend-amar_badral/32/219656_2.png) [@Mend-Amar\_Badral](https://discourse.julialang.org/u/Mend-Amar_Badral)\
**Post date:** [June 27, 2025, 1:22am UTC](https://discourse.julialang.org/t/precompilation-for-almost-every-package-that-i-use-even-though-i-used-that-package-before/130265/1 "2025-06-27T01:22:54Z")

</div>

So I use julia v1.10. I for example, open up julia session and then activate shared environment like so:

```julia
(@geo) pkg> activate --shared ml3d
  Activating project at `~/.julia/environments/ml3d`

(@ml3d) pkg> st
Status `~/.julia/environments/ml3d/Project.toml`
⌅ [052768ef] CUDA v5.7.3
⌃ [587475ba] Flux v0.16.3
  [991e6b22] GaussianSplatting v1.0.1 `https://github.com/JuliaNeuralGraphics/GaussianSplatting.jl.git#main`
⌃ [02a925ec] cuDNN v1.4.2
Info Packages marked with ⌃ and ⌅ have new versions available. Those with ⌃ may be upgradable, but those with ⌅ are restricted by compatibility constraints from upgrading. To see why use `status --outdated`

```

And then when I use the CUDA package, it must be precompiled.

```julia
julia> using CUDA
[Info: Precompiling CUDA [052768ef-5323-5732-b1bb-66c8b64840ba]
Precompiling AtomixCUDAExt finished.
  1 dependency successfully precompiled in 47 seconds. 72 already precompiled.
[Info: Precompiling AtomixCUDAExt [13011619-4c7c-5ef0-948f-5fc81565cd05]
┌ Warning: Module CUDA with build ID fafbfcfd-ce1c-4354-0000-078a6d9ddb67 is missing from the cache.
│ This may mean CUDA [052768ef-5323-5732-b1bb-66c8b64840ba] does not support precompilation but is imported by a module that does.
└ @ Base loading.jl:2018
[Info: Skipping precompilation since __precompile__ (false). Importing AtomixCUDAExt [13011619-4c7c-5ef0-948f-5fc81565cd05].

```

This happens to every other environment that is not the main v1.10 environment.

```julia
(@v1.10) pkg> activate --shared geo
  Activating project at `~/.julia/environments/geo`

julia> using Geo

GeoIO
GeoStats
julia> using GeoStats
[Info: Precompiling GeoStats [dcc97b0b-8ce5-5539-9008-bb190f959ef6]

```

Is this some kind of bug? I remember before I upgraded to v1.11, I had perfectly good environments set up. I later downgraded to v1.10 but still packages need precompilation on every turn of environment. (I kinda saw somewhere that it’s v1.11 issue such that you need to start julia with `julia --project` ?

Edit: Turns out `julia --project` works.

```julia
julia --project=~/.julia/environments/ml3d
               _
   _ _ _(_)_ | Documentation: https://docs.julialang.org
  (_) | (_) (_) |
   _ _ _| |_ __ _ | Type "?" for help, "]?" for Pkg help.
  | | | | | | |/ _` | |
  | | |_| | | | (_| | | Version 1.10.9 (2025-03-10)
 _/ |\ __'_|_|_|\__'_| | Official https://julialang.org/ release
|__/ |

julia> using CUDA

```

But still why xD?

---

<div class="post-metadata">

**Author:** ![Benny](https://avatars.discourse-cdn.com/v4/letter/b/49beb7/32.png) [@Benny](https://discourse.julialang.org/u/Benny)\
**Post date:** [June 27, 2025, 5:43am UTC](https://discourse.julialang.org/t/precompilation-for-almost-every-package-that-i-use-even-though-i-used-that-package-before/130265/2 "2025-06-27T05:43:29Z")

</div>

Hard to say if there’s anything strange going on because it’s not clear what conditions this is happening in. I don’t use custom shared environments, so I tried to make one for Julia v1.10 real quick, though installing `GeoStats` wasn’t quick at all.

> **After that, I could activate it from the REPL in new processes then import \`GeoStats\` without precompilation kicking in.**
>
> ```julia
> PS C:\Users\Benny> julia +1.10
> _
> _ _ _(_)_ | Documentation: https://docs.julialang.org
> (_) | (_) (_) |
> _ _ _| |_ __ _ | Type "?" for help, "]?" for Pkg help.
> | | | | | | |/ _` | |
> | | |_| | | | (_| | | Version 1.10.9 (2025-03-10)
> _/ |\ __'_|_|_|\__'_| | Official https://julialang.org/ release
> |__/ |
> 
> (@v1.10) pkg> activate --shared blah11
> Activating project at `C:\Users\Benny\.julia\environments\blah11`
> 
> julia> using GeoStats
> 
> julia>
> 
> ```

So that `GeoStats` precompilation might not be fine. The ` __precompile__ (false)` for `AtomixCUDAExt` definitely doesn’t seem fine, but I don’t use `Atomix` so I don’t know.

Still, depending on what you were doing, some of the precompilation could have been reasonably triggered. A precompiled package doesn’t depend only on the package and its particular version. It also depends on the Julia version (which determines the compiler itself), the compatible versions of every other package in a given environment, and in bad cases the package versions irreversibly loaded into a process prior to activating an environment with contradicting versions. If any of those change, we need some (often not all) different precompiled packages, and only 10 per package are stored in the precompiled cache by default ([`JULIA_MAX_NUM_PRECOMPILE_FILES`](https://docs.julialang.org/en/v1/manual/environment-variables/#JULIA_MAX_NUM_PRECOMPILE_FILES)). Worst case if I’m cycling through \>10 different environments with different versions of a package, I’m triggering its precompilation every process.

---

<div class="post-metadata">

**Author:** ![tim.holy](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/tim.holy/32/52_2.png) [@tim.holy](https://discourse.julialang.org/u/tim.holy)\
**Post date:** [June 27, 2025, 7:01am UTC](https://discourse.julialang.org/t/precompilation-for-almost-every-package-that-i-use-even-though-i-used-that-package-before/130265/3 "2025-06-27T07:01:09Z")

</div>

Does this still happen with `julia --startup-file=no`? If that fixes it, it implies there’s a package that’s loaded during startup with a version that’s incompatible with something in the `ml3d` environment.

---

<div class="post-metadata">

**Author:** ![Mend-Amar\_Badral](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/mend-amar_badral/32/219656_2.png) [@Mend-Amar\_Badral](https://discourse.julialang.org/u/Mend-Amar_Badral)\
**Post date:** [June 28, 2025, 1:34am UTC](https://discourse.julialang.org/t/precompilation-for-almost-every-package-that-i-use-even-though-i-used-that-package-before/130265/4 "2025-06-28T01:34:16Z")

</div>

I tried `julia --startup-fle`. @tim.holy’s method works.

```julia
(@v1.10) pkg> activate --shared geo
  Activating project at `~/.julia/environments/geo`

julia> using GeoStats

julia>

```

But with the regular `julia` command, not working.

```julia
julia> using GeoStats
[Info: Precompiling GeoStats [dcc97b0b-8ce5-5539-9008-bb190f959ef6]
┌ Warning: attempting to remove probably stale pidfile
│ path = "/home/mendee/.julia/compiled/v1.10/CoDa/7XhLd_iAgAA.ji.pidfile"
└ @ FileWatching.Pidfile ~/.julia/juliaup/julia-1.10.9+0.x64.linux.gnu/share/julia/stdlib/v1.10/FileWatching/src/pidfile.jl:244
┌ Warning: attempting to remove probably stale pidfile
│ path = "/home/mendee/.julia/compiled/v1.10/Distributions/xILW0_iAgAA.ji.pidfile"
└ @ FileWatching.Pidfile ~/.julia/juliaup/julia-1.10.9+0.x64.linux.gnu/share/julia/stdlib/v1.10/FileWatching/src/pidfile.jl:244

```

I have on my `startup.jl`

```julia
try
    using Revise
catch e
    @warn "Error initializing Revise" exception=(e, catch_backtrace())
end
#atreplinit() do repl
    @eval using OhMyREPL
    @eval colorscheme!("GruvboxDark")
#end
#
Base.identify_package("CondaPkg") === nothing || Base.require(@ __MODULE__ , :CondaPkg)

Base.identify_package("PreferenceTools") === nothing || Base.require(@ __MODULE__ , :PreferenceTools)

ENV["JULIA_EDITOR"] = "nvim";

ENV["RASTERDATASOURCES_PATH"] = "/home/mendee/Data/"

```

Does this mean Revise, PreferenceTools and OhMyREPL packages causing the error?

---

<div class="post-metadata">

**Author:** ![tim.holy](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/tim.holy/32/52_2.png) [@tim.holy](https://discourse.julialang.org/u/tim.holy)\
**Post date:** [June 28, 2025, 7:35am UTC](https://discourse.julialang.org/t/precompilation-for-almost-every-package-that-i-use-even-though-i-used-that-package-before/130265/5 "2025-06-28T07:35:12Z")

</div>

It means that at least one package is:

- in your default environment _and_ a dependency of your project environment
- loaded by your `startup.jl` (since you’re using Revise, the “culprit” is most likely OrderedCollections.jl)
- resolved to different versions in your default `Manifest.toml` and your project’s `Manifest.toml`

You may have precompiled your project and its dependencies using the project’s `Manifest.toml`, but then when you start a new session without `julia --project`, you load the culprit with the version resolved in the default environment. Thus all project code that depends on that package needs to be recompiled.

`julia --project` ensures that all package versions are taken from the project, even those loaded by your `startup.jl`. Thus there is no version conflict and you can use the code you previously precompiled.

---

<div class="post-metadata">

**Author:** ![Mend-Amar\_Badral](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/mend-amar_badral/32/219656_2.png) [@Mend-Amar\_Badral](https://discourse.julialang.org/u/Mend-Amar_Badral)\
**Post date:** [June 28, 2025, 8:21am UTC](https://discourse.julialang.org/t/precompilation-for-almost-every-package-that-i-use-even-though-i-used-that-package-before/130265/6 "2025-06-28T08:21:41Z")

</div>

Thanks for detailed explanation. So, going forward, I will be using `julia --project` if possible.