| 23 Jul 2025 |
 apyh | pr opened 😁 | 16:59:39 |
 Gaétan Lepage | Can you share the link apyh? | 22:56:02 |
| apyh | ah sure! https://github.com/NixOS/nixpkgs/pull/427804 | 23:00:23 |
| apyh | they added a bunch of new stuff so i have to patch the shebang in a second python script. surprisingly didn't cause a build failure without it, just didn't export some of the new symbols | 23:01:02 |
| Gaétan Lepage | Thanks! | 23:03:49 |
| 24 Jul 2025 |
| apyh | huh. thanks for the nixpkgs-review. very strange to me that it fails to build pytorch as a result, but that the python 3.13 failure is just a bunch of .. warnings inside torch? i'll compile again locally to see.. | 14:56:24 |
| apyh | can't repro the build failure locally for python312Packages.torchWithCuda Gaétan Lepage 🤔
left a comment here to that effect https://github.com/NixOS/nixpkgs/pull/427804#issuecomment-3114819745 | 20:26:13 |
| apyh | can't repro any of the build failures in fact, only took 3.5 hours per torch to test 😭 | 23:51:03 |
| 25 Jul 2025 |
| Gaétan Lepage | It probably failed because of flakiness | 10:57:16 |
| apyh | rebased it btw :) | 17:29:53 |
| apyh | both builds worked fine on my machine.. does nixpkgs-review have a timeout? lol | 17:30:06 |
| apyh | i have a 7800x3d and it still took 3.5 hours per torch build | 17:30:26 |
| 26 Jul 2025 |
 Tristan Ross | Is that a PR that my 128 cores could be useful with? | 00:34:02 |
| apyh | haha i mean, if you have the ram to match ;) | 01:07:29 |
| apyh | it builds fine on my end - just a verification from someone else would be nice :) | 01:07:40 |
|  oak 🏳️🌈♥️ changed their profile picture. | 08:29:04 |
| Gaétan Lepage | Any objection to merging the nccl bump?
https://github.com/NixOS/nixpkgs/pull/427804 | 09:26:39 |
| 3 Aug 2025 |
 connor (burnt/out) (UTC-8) | As a heads up, I’ll be removing CUDA versions prior to 11.8 from Nixpkgs and moving them to https://github.com/nix-community/cuda-legacy so they’ll be available as an overlay using the cool new functionality I got merged over the last few months to make it easier to extend CUDA stuff out of tree | 19:12:49 |
| 4 Aug 2025 |
 aidalgol | I'm trying to write a derivation for https://github.com/alicevision/popsift/ and the configure phase fails because it cant find "cudadevrt".
CMake Error: The following variables are used in this project, but they are set to NOTFOUND.
Please set them or make sure they are set and tested correctly in the CMake files:
CUDA_CUDADEVRT_LIBRARY
linked by target "popsift" in directory /build/source/src
linked by target "popsift-match" in directory /build/source/src/application
linked by target "popsift-demo" in directory /build/source/src/application
CUDA_cudadevrt_LIBRARY (ADVANCED)
linked by target "popsift" in directory /build/source/src
I haven't been able to find much about this beyond that it is the CUDA Device Runtime library. A grep for "devrt" on nixpkgs turns up nothing. Anyone here know about this CUDA library?
| 11:00:58 |
 Robbie Buxton | It might be the dev output of cuda_cudart, I.e cuda_cudart.dev | 11:02:21 |
| Robbie Buxton | I remember running into something similar in the past and I think I fixed it that way but might be misremembering | 11:03:16 |
| aidalgol | Yay, now I'm on to compilation errors! | 11:05:39 |
| aidalgol | Looks like this will only build on ooold CUDA versions. | 11:06:05 |
| aidalgol | nvcc fatal : Unsupported gpu architecture 'compute_35'
| 11:06:18 |
| aidalgol | I want to get meshroom in nixpkgs, and it appears that all the CUDA parts are still targeting CUDA pre-11. | 11:07:08 |
| connor (burnt/out) (UTC-8) | Are they manually specifying compute capabilities in the source build system? If so, generally those can be patched out. | 14:41:22 |
| connor (burnt/out) (UTC-8) | Try using the latest commit and make sure to set https://github.com/alicevision/popsift/blob/8623b697ac632f40d74f8773d646d6a804e89893/CMakeLists.txt#L14 | 14:46:54 |
| connor (burnt/out) (UTC-8) | Inside the flags attribute of the CUDA package set (https://github.com/NixOS/nixpkgs/blob/7306c79fa2fd9483e7abd32e8637fc7f20344cbd/pkgs/top-level/cuda-packages.nix#L104) we have a helper attribute (https://github.com/NixOS/nixpkgs/blob/7306c79fa2fd9483e7abd32e8637fc7f20344cbd/pkgs/development/cuda-modules/_cuda/lib/strings.nix#L196) which you can use to set that CMake variable | 14:49:07 |
| connor (burnt/out) (UTC-8) | Example usage: https://github.com/NixOS/nixpkgs/blob/36590ed03f5cd09054978e927af3eb41e89fe838/pkgs/by-name/ll/llama-cpp/package.nix#L140 | 14:49:46 |
| connor (burnt/out) (UTC-8) | It’s not documented because there’s basically never time for anything lmao 😭 | 14:50:15 |
