| 4 Dec 2025 |
 Alexandros Liarokapis | and it is apparently in the nixos cache by defualt? | 14:05:18 |
| Alexandros Liarokapis | * and it is apparently in the nixos cache by default? | 14:16:57 |
 Gaétan Lepage | I'm not sure torchWithCuda will be.
For `cudaSupport-enabled packages, consider using the Flox binary cache, or the NixOS-CUDA one. | 14:28:52 |
 connor (burnt/out) (UTC-8) | I’ll try to answer this later today. Depending on how comfortable you are with Nix, pull in the overlay for CUDA-legacy (https://github.com/nixos-cuda/cuda-legacy) to add a bunch of manifests and then customize the package set to your liking by using override on the CUDA package set and providing the manifest version you want. The docs are lacking an example for this.
As you discovered, NVCC may support capabilities but that doesn’t mean the big libraries most people use (cuDNN, libcublas, TensorRT, etc.) do. We have the unenviable job of either adopting the latest release for each version or fixing them in time and never updating. The decision is made more difficult by the fact NVIDIA seems to fix bugs by doing major/minor releases much more often than patch releases.
The trace-verbose thing is handy but undocumented and only exists because implementations of the Problems RFC keep getting bikeshedded to death.
We should probably have a section in the CUDA docs which list supported capabilities for each package set. Could be automatically generated given I added the available capabilities for each release to backendStdenv.
| 16:28:20 |
| connor (burnt/out) (UTC-8) | god i hate computers | 16:29:35 |
| connor (burnt/out) (UTC-8) | Reminder to self: post about changes I’ve been working on / need (fix adding attributes to backendStdenv, nvcc multiple outputs again, ccache) | 16:33:13 |
 SomeoneSerge (back on matrix) |
problems rfc
Tha release was cut off, IMO we should push a half-assed partial impl as per my closed PR in, bc 99% of the features we don't care about
| 19:52:52 |
| SomeoneSerge (back on matrix) |
stdenv attributes
...also nuke the other 90% attributes that don't actually belong and aren't even used
| 19:53:40 |
 corroding556 | Thank you so much! cuda-legacy was exactly what I needed.
Managed to get the configuration successfully built and deployed, going to try out an application which uses CUDA soon to verify everything is in working order.
Unenviable does seem like an appropriate word, digging into all this really made me appreciate how much work goes into making any of this possible.
Pointing folks like myself on older/unsupported hardware towards cuda-legacy (an example in the wiki/manual would be great) seems like a reasonable way to do things. | 23:52:06 |
| 5 Dec 2025 |
| connor (burnt/out) (UTC-8) | Changes I've been working on:
- https://github.com/NixOS/nixpkgs/pull/467975
- https://github.com/NixOS/nixpkgs/pull/467976 (both nvcc.profile and reintroducing multiple outputs for nvcc)
| 02:05:17 |
 Kevin Mittman (UTC-7) | So CUDA 13.1 released today
https://developer.download.nvidia.com/compute/cuda/redist/redistrib_13.1.0.json | 03:34:00 |
| Kevin Mittman (UTC-7) | Now includes a binary archive tarball for cuda_compat (not for Jetson Orin) "forward compatibility" | 03:36:07 |
| 4 Aug 2022 |
|  Winter (she/her) joined the room. | 03:26:42 |
| Winter (she/her) | (hi, just came here to read + respond to this.) | 03:28:52 |
 tpw_rules | hey. i had previously sympathzied with samuela and like i said before had some of the same frustrations. i just edited my github comment to add "[CUDA] packages are universally complicated, fragile to package, and critical to daily operations. Nix being able to manage them is unbelievably helpful to those of us who work with them regularly, even if support is downgraded to only having an expectation of function on stable branches." | 03:29:14 |
| Winter (she/her) | In reply to @tpw_rules:matrix.org
i'm mildly peeved about a recent merging of something i maintain where i'm pretty sure the merger does not own the expensive hardware required to properly test the package. i don't think it broke anything but i was given precisely 45 minutes to see the notification before somebody merged it ugh, 45 minutes? that's... not great. not to air dirty laundry but did you do what samuela did in the wandb PR and at least say that that wasn't a great thing to do? (not sure how else to word that, you get what i mean) | 03:30:23 |
| tpw_rules | no, i haven't yet, but i probably will | 03:31:03 |
| Winter (she/her) | i admittedly did that with a PR once, i forget how long the maintainer was requested for but i merged it because multiple people reported it fixed the issue. the maintainer said "hey, don't do that" after and now i do think twice before merging. so it could help, is what i'm saying. | 03:31:50 |
| tpw_rules | i'm not sure what went wrong with the wandb PR anyway, i think it was just a boneheaded move on the maintainer's part | 03:32:10 |
| Winter (she/her) | (it was also simple enough that it was fine and the maintainer said it looked good after) | 03:32:15 |
| tpw_rules | * i'm not sure what went wrong with the wandb PR anyway, i think it was just a boneheaded move on the merger's part | 03:32:19 |
| tpw_rules | but i thought most of the frustration was around packages which don't really involve CUDA breaking the fragile CUDA packages, and i'm not sure how the warning helps in this case. it's not like nixpkgs-review prints out the comments. maybe i'm wrong. but it is a legitimate problem | 03:34:19 |
| Winter (she/her) | the frustration that i see is that people are touching packages that he maintains, am i missing further context here? | 03:35:09 |
| tpw_rules | did you ever see this? https://discourse.nixos.org/t/nixpkgss-current-development-workflow-is-not-sustainable/18741 | 03:35:43 |
| Winter (she/her) | oh yes i did | 03:35:49 |
| Winter (she/her) | but that's not what the topic of this PR/the notice is, though? | 03:36:11 |
| Winter (she/her) | this wouldn't help that | 03:36:14 |
| Winter (she/her) | ~~is that what you're saying and i'm just lagging behind~~ | 03:36:27 |
| tpw_rules | no it wouldn't, but it reads to me like that's the underlying problem and this is a manifestation which can be controlled more easily. not to put thoughts in people's head | 03:37:07 |
| Winter (she/her) | right
(what do you mean by that last sentence, you don't want to influence anyone's opinion on the matter by saying that?) | 03:38:29 |
