Thanks connor (he/him) (UTC+2) .

I can now launch the triton test.

However, when attempting to launch tests on the unstloth library, nix builds Torch for Python313 instead of Python 312.
Torch is not supported on Python 3.13 yet - it still attempts to build however which confuses me.

diff --git a/pkgs/development/python-modules/unsloth/default.nix b/pkgs/development/python-modules/unsloth/default.nix
index 73f94721b5e0..e6473c3bfa1d 100644
--- a/pkgs/development/python-modules/unsloth/default.nix
+++ b/pkgs/development/python-modules/unsloth/default.nix
@@ -27,6 +27,9 @@
   hf-transfer,
   diffusers,
   torchvision,
+
+  # tests
+  cudaPackages,
 }:
 
 buildPythonPackage rec {
@@ -85,6 +88,19 @@ buildPythonPackage rec {
   # NotImplementedError: Unsloth: No NVIDIA GPU found? Unsloth currently only supports GPUs!
   dontUsePythonImportsCheck = true;
 
+  passthru.tests = {
+    import-cuda = cudaPackages.writeGpuTestPython
+      {
+        libraries = ps: [
+          ps.torch
+        ];
+      }
+      ''
+        import unsloth
+        unsloth.test()
+      '';
+  };
+
   meta = {
     description = "Finetune Llama 3.3, DeepSeek-R1 & Reasoning LLMs 2x faster with 70% less memory";
     homepage = "https://github.com/unslothai/unsloth";

nix-build -I nixpkgs=. --arg config '{ allowUnfree = true; cudaSupport = true;}' -A python312Packages.unsloth.tests.import-cuda

I managed to launch a test on my package with CUDA enabled, but I get an issue from triton not finding a C compiler. Does that ring a bell to someone ?

RuntimeError: Failed to find C compiler. Please specify via CC environment variable or set triton.knobs.build.impl.

I share my work in progress in a draft PR here: https://github.com/NixOS/nixpkgs/pull/441728

In reply to @hugo:okeso.eu

I managed to launch a test on my package with CUDA enabled, but I get an issue from triton not finding a C compiler. Does that ring a bell to someone ?

RuntimeError: Failed to find C compiler. Please specify via CC environment variable or set triton.knobs.build.impl.

I share my work in progress in a draft PR here: https://github.com/NixOS/nixpkgs/pull/441728

adrian-gierakowski:

!!! Exception during processing !!! HIP error: invalid device function
HIP kernel errors might be asynchronously reported at some other API call, so the stacktrace below might be incorrect.
For debugging consider passing AMD_SERIALIZE_KERNEL=3
Compile with `TORCH_USE_HIP_DSA` to enable device-side assertions.

Traceback (most recent call last):
  File "/nix/store/dg5g3ypdsjvy0274156l74klx4wr0nbx-comfyui-unstable-2025-09-06/lib/python3.13/site-packages/execution.py", line 496, in execute
    output_data, output_ui, has_subgraph, has_pending_tasks = await get_output_data(prompt_id, unique_id, obj, input_data_all, execution_block_cb=execution_block_cb, pre_execute_cb=pre_execute_cb, hidden_inputs=hidden_inputs)
                                                              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/nix/store/dg5g3ypdsjvy0274156l74klx4wr0nbx-comfyui-unstable-2025-09-06/lib/python3.13/site-packages/execution.py", line 315, in get_output_data
    return_values = await _async_map_node_over_list(prompt_id, unique_id, obj, input_data_all, obj.FUNCTION, allow_interrupt=True, execution_block_cb=execution_block_cb, pre_execute_cb=pre_execute_cb, hidden_inputs=hidden_inputs)
                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/nix/store/dg5g3ypdsjvy0274156l74klx4wr0nbx-comfyui-unstable-2025-09-06/lib/python3.13/site-packages/execution.py", line 289, in _async_map_node_over_list
    await process_inputs(input_dict, i)
  File "/nix/store/dg5g3ypdsjvy0274156l74klx4wr0nbx-comfyui-unstable-2025-09-06/lib/python3.13/site-packages/execution.py", line 277, in process_inputs
    result = f(**inputs)
  File "/nix/store/dg5g3ypdsjvy0274156l74klx4wr0nbx-comfyui-unstable-2025-09-06/lib/python3.13/site-packages/nodes.py", line 74, in encode
    return (clip.encode_from_tokens_scheduled(tokens), )
            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^
  File "/nix/store/dg5g3ypdsjvy0274156l74klx4wr0nbx-comfyui-unstable-2025-09-06/lib/python3.13/site-packages/comfy/sd.py", line 170, in encode_from_tokens_scheduled
    pooled_dict = self.encode_from_tokens(tokens, return_pooled=return_pooled, return_dict=True)
  File "/nix/store/dg5g3ypdsjvy0274156l74klx4wr0nbx-comfyui-unstable-2025-09-06/lib/python3.13/site-packages/comfy/sd.py", line 232, in encode_from_tokens
    o = self.cond_stage_model.encode_token_weights(tokens)
  File "/nix/store/dg5g3ypdsjvy0274156l74klx4wr0nbx-comfyui-unstable-2025-09-06/lib/python3.13/site-packages/comfy/sd1_clip.py", line 689, in encode_token_weights
    out = getattr(self, self.clip).encode_token_weights(token_weight_pairs)
  File "/nix/store/dg5g3ypdsjvy0274156l74klx4wr0nbx-comfyui-unstable-2025-09-06/lib/python3.13/site-packages/comfy/sd1_clip.py", line 45, in encode_token_weights
    o = self.encode(to_encode)
  File "/nix/store/dg5g3ypdsjvy0274156l74klx4wr0nbx-comfyui-unstable-2025-09-06/lib/python3.13/site-packages/comfy/sd1_clip.py", line 291, in encode
    return self(tokens)
  File "/nix/store/jzm64j9dp50xs770h3w7n8h9pj6mpkjp-python3.13-torch-2.8.0/lib/python3.13/site-packages/torch/nn/modules/module.py", line 1773, in _wrapped_call_impl
    return self._call_impl(*args, **kwargs)
           ~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^
  File "/nix/store/jzm64j9dp50xs770h3w7n8h9pj6mpkjp-python3.13-torch-2.8.0/lib/python3.13/site-packages/torch/nn/modules/module.py", line 1784, in _call_impl
    return forward_call(*args, **kwargs)
  File "/nix/store/dg5g3ypdsjvy0274156l74klx4wr0nbx-comfyui-unstable-2025-09-06/lib/python3.13/site-packages/comfy/sd1_clip.py", line 253, in forward
    embeds, attention_mask, num_tokens, embeds_info = self.process_tokens(tokens, device)
                                                      ~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^
  File "/nix/store/dg5g3ypdsjvy0274156l74klx4wr0nbx-comfyui-unstable-2025-09-06/lib/python3.13/site-packages/comfy/sd1_clip.py", line 204, in process_tokens
    tokens_embed = self.transformer.get_input_embeddings()(tokens_embed, out_dtype=torch.float32)
  File "/nix/store/jzm64j9dp50xs770h3w7n8h9pj6mpkjp-python3.13-torch-2.8.0/lib/python3.13/site-packages/torch/nn/modules/module.py", line 1773, in _wrapped_call_impl
    return self._call_impl(*args, **kwargs)
           ~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^
  File "/nix/store/jzm64j9dp50xs770h3w7n8h9pj6mpkjp-python3.13-torch-2.8.0/lib/python3.13/site-packages/torch/nn/modules/module.py", line 1784, in _call_impl
    return forward_call(*args, **kwargs)
  File "/nix/store/dg5g3ypdsjvy0274156l74klx4wr0nbx-comfyui-unstable-2025-09-06/lib/python3.13/site-packages/comfy/ops.py", line 270, in forward
    return self.forward_comfy_cast_weights(*args, **kwargs)
           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^
  File "/nix/store/dg5g3ypdsjvy0274156l74klx4wr0nbx-comfyui-unstable-2025-09-06/lib/python3.13/site-packages/comfy/ops.py", line 266, in forward_comfy_cast_weights
    return torch.nn.functional.embedding(input, weight, self.padding_idx, self.max_norm, self.norm_type, self.scale_grad_by_freq, self.sparse).to(dtype=output_dtype)
           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/nix/store/jzm64j9dp50xs770h3w7n8h9pj6mpkjp-python3.13-torch-2.8.0/lib/python3.13/site-packages/torch/nn/functional.py", line 2546, in embedding
    return torch.embedding(weight, input, padding_idx, scale_grad_by_freq, sparse)
           ~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
torch.AcceleratorError: HIP error: invalid device function
HIP kernel errors might be asynchronously reported at some other API call, so the stacktrace below might be incorrect.
For debugging consider passing AMD_SERIALIZE_KERNEL=3
Compile with `TORCH_USE_HIP_DSA` to enable device-side assertions.

Actually, with the HSA override to 11.0.0 it worked, but I get a different kind of error

loaded completely 30779.053608703613 1639.406135559082 True
  0%|                                    | 0/1 [00:00<?, ?it/s:0:rocdevice.cpp            :3020: 78074348282d us:  Callback: Queue 0x7f831c600000 aborting with error : HSA_STATUS_ERROR_INVALID_ISA: The instruction set architecture is invalid. code: 0x100f

Actually, with the HSA override to 11.0.0 it worked, but I get a different kind of error

  0%|                                    | 0/1 [00:00<?, ?it/s:0:rocdevice.cpp            :3020: 78074348282d us:  Callback: Queue 0x7f831c600000 aborting with error : HSA_STATUS_ERROR_INVALID_ISA: The instruction set architecture is invalid. code: 0x100f
Aborted                    (core dumped) command nix "$@"```

In reply to @layus:matrix.org
Is this team involved in flox/nvidia partnership ?
(See https://flox.dev/cuda/)
I guess so since the nixos foundation also is, but there is no mention of this team or its amazing work.