# CUDA.jl not loading in julia 1.12.0
**URL:** https://discourse.julialang.org/t/cuda-jl-not-loading-in-julia-1-12-0/133022
**Category:** General Usage
**Created:** [October 9, 2025, 6:29pm UTC](https://discourse.julialang.org/t/cuda-jl-not-loading-in-julia-1-12-0/133022 "2025-10-09T18:29:20Z")
**Posts on this page:** 11
**Page:** 1
### Author:  [@Ferran\_Mazzanti](https://discourse.julialang.org/u/Ferran_Mazzanti)
#### Post date: [October 9, 2025, 6:29pm UTC](https://discourse.julialang.org/t/cuda-jl-not-loading-in-julia-1-12-0/133022/1 "2025-10-09T18:29:20Z")
Hi,
I’ve just upgraded from 1.11.7 to 1.12.0 and went though the packages installation from scratch. I installed CUDA.jl from pkg.add() and it did install fine. I then restarted the machine to make sure all is clear, and when opened julia 1.12.0 and issued the ‘using CUDA’ command, it just sits there doing nothing, essentially forever (20+ minutes waiting and still nothing). I changed nothing else but julia in my ubuntu machine, and everything was working fine before, prior to the upgrade…
Any clues here?
Best,
Ferran.
---
### Author:  [@ufechner7](https://discourse.julialang.org/u/ufechner7)
#### Post date: [October 9, 2025, 7:20pm UTC](https://discourse.julialang.org/t/cuda-jl-not-loading-in-julia-1-12-0/133022/2 "2025-10-09T19:20:04Z")
Can you share the output of:
```julia-auto
using Pkg
Pkg.status()
```
?
---
### Author:  [@Ferran\_Mazzanti](https://discourse.julialang.org/u/Ferran_Mazzanti)
#### Post date: [October 9, 2025, 7:32pm UTC](https://discourse.julialang.org/t/cuda-jl-not-loading-in-julia-1-12-0/133022/3 "2025-10-09T19:32:11Z")
sure
julia\> Pkg.status()
Status `~/.julia/environments/v1.12/Project.toml`
[052768ef] CUDA v5.9.0
[944b1d66] CodecZlib v0.7.8
[7a1cc6ca] FFTW v1.10.0
[59287772] Formatting v0.4.3
[7073ff75] IJulia v1.30.6
[bac558e1] OrderedCollections v1.8.1
[d330b81b] PyPlot v2.11.6
---
### Author:  [@Ferran\_Mazzanti](https://discourse.julialang.org/u/Ferran_Mazzanti)
#### Post date: [October 10, 2025, 7:26am UTC](https://discourse.julialang.org/t/cuda-jl-not-loading-in-julia-1-12-0/133022/4 "2025-10-10T07:26:13Z")
Uh… no apparent solution, right? I wonder if anybody else here has tried that and can report on her/his experience with the upgrade and CUDA.
In the meantime I don’t know what to do… revert to the previous julia version?
---
### Author:  [@nilshg](https://discourse.julialang.org/u/nilshg)
#### Post date: [October 10, 2025, 7:59am UTC](https://discourse.julialang.org/t/cuda-jl-not-loading-in-julia-1-12-0/133022/5 "2025-10-10T07:59:31Z")
I can’t reproduce this on a Windows 11 machine, the first `using CUDA` was indeed quite slow (on the order of a couple of minutes) but things work fine.
---
### Author:  [@Ferran\_Mazzanti](https://discourse.julialang.org/u/Ferran_Mazzanti)
#### Post date: [October 10, 2025, 8:46am UTC](https://discourse.julialang.org/t/cuda-jl-not-loading-in-julia-1-12-0/133022/6 "2025-10-10T08:46:28Z")
Then this may be OS-dependent. The only way I’ve managed to make it work on my ubuntu mate machine is to invoke julia with the command
julia --compiled-modules=no
then it takes a while to load -but it does load, contrarily to what happened before…
---
### Author:  [@nilshg](https://discourse.julialang.org/u/nilshg)
#### Post date: [October 10, 2025, 10:25am UTC](https://discourse.julialang.org/t/cuda-jl-not-loading-in-julia-1-12-0/133022/7 "2025-10-10T10:25:07Z")
Just tried in Ubuntu WSL2 and it’s much speedier there:
```julia-auto
julia> @time using CUDA
17.013851 seconds (12.21 M allocations: 715.201 MiB, 1.71% gc time, 83.69% compilation time: 98% of which was recompilation)
```
---
### Author:  [@Ferran\_Mazzanti](https://discourse.julialang.org/u/Ferran_Mazzanti)
#### Post date: [October 10, 2025, 7:16pm UTC](https://discourse.julialang.org/t/cuda-jl-not-loading-in-julia-1-12-0/133022/8 "2025-10-10T19:16:47Z")
Ok, looks like there is a bug in the synchronization of parallel loading tasks… or something similar 🙂 At least that’s what claude anthropic told me. And he found the following workaround, which is to edit the .julia/config/startup.jl file and add the following line:
ENV[“JULIA\_DEBUG”] = “loading”
which is a bit annoying because it spits a lot of messages you don’t really want to see on the screen every time you load a package… but it makes it work. Claude also says that is something that has been also reported by other users, andhope to find a fix in julia 1.12.1. Please notice I’ve tried that in 4 different machines running ubuntu.
Bottom line is: there’s a bug but also a workaround.
---
### Author:  [@sob](https://discourse.julialang.org/u/sob)
#### Post date: [October 10, 2025, 7:40pm UTC](https://discourse.julialang.org/t/cuda-jl-not-loading-in-julia-1-12-0/133022/9 "2025-10-10T19:40:58Z")
```julia-auto
julia> CUDA.versioninfo()
CUDA toolchain:
- runtime 13.0, artifact installation
- driver 580.76.5 for 13.0
- compiler 13.0
CUDA libraries:
- CUBLAS: 13.0.2
- CURAND: 10.4.0
- CUFFT: 12.0.0
- CUSOLVER: 12.0.4
- CUSPARSE: 12.6.3
- CUPTI: 2025.3.1 (API 13.0.1)
- NVML: 13.0.0+580.76.5
Julia packages:
- CUDA: 5.9.0
- CUDA_Driver_jll: 13.0.1+0
- CUDA_Compiler_jll: 0.2.1+0
- CUDA_Runtime_jll: 0.19.1+0
Toolchain:
- Julia: 1.12.0
- LLVM: 18.1.7
1 device:
0: NVIDIA GeForce RTX 5090 (sm_120, 30.470 GiB / 31.843 GiB available)
julia> CUDA.functional()
true
```
---
### Author:  [@maleadt](https://discourse.julialang.org/u/maleadt)
#### Post date: [October 11, 2025, 5:57am UTC](https://discourse.julialang.org/t/cuda-jl-not-loading-in-julia-1-12-0/133022/10 "2025-10-11T05:57:02Z")
CUDA.jl 1.12 compatibility is in the works. Try the master branch if you run into issues.
> [@Ferran\_Mazzanti](#):
>
> when opened julia 1.12.0 and issued the ‘using CUDA’ command, it just sits there doing nothing, essentially forever (20+ minutes waiting and still nothing)
Interrupt it (CTRL-C) and post the backtrace.
> [@Ferran\_Mazzanti](#):
>
> Ok, looks like there is a bug in the synchronization of parallel loading tasks… or something similar 🙂 At least that’s what claude anthropic told me. And he found the following workaround, which is to edit the .julia/config/startup.jl file and add the following line:
>
> ENV[“JULIA\_DEBUG”] = “loading”
Don’t trust LLMs to debug issues like this. Adding debug logging only increases verbosity, and is not expected to be a valid workaround for anything.
---
### Author:  [@Ferran\_Mazzanti](https://discourse.julialang.org/u/Ferran_Mazzanti)
#### Post date: [October 11, 2025, 8:06am UTC](https://discourse.julialang.org/t/cuda-jl-not-loading-in-julia-1-12-0/133022/11 "2025-10-11T08:06:57Z")
Hi,
‘trusting’ is not the right word, but in any case Claude has given me a way (other than downgrading to a previous version) to keep running my production codes. Actually it is the only one who has done so. I would say that a sentence like ‘Adding debug logging only increases verbosity, and is not expected to be a valid workaround for anything’ simply means that, at least in this case, the problem is not yet fully understood. Maybe adding the verbosity level has some side effects that are among the ‘not expected’ things. I don’t know as I’m not a julia develope. The only thing I can say is that this is indeed a workaround, as it makes things work (and with that I mean more than just returning the prompt after the ‘using CUDA’, I mean to have codes running again and working as before), while I understand this can’t be the solution, which should come in the (near?) future…