chore: add pixi for cuda-core and cuda-bindings by cpcloud · Pull Request #1226 · NVIDIA/cuda-python

cpcloud · 2025-11-07T21:28:13Z

This PR is a redo of pixi environment setup that combines cuda-core and
cuda-bindings into a single PR.

I am not trying to capture every possible environment combination of CUDA and
Python right now, just enough to get a minimal development environment working
for both of these projects on linux-64. What's in these pixi.toml files is
the scope I intended.

The biggest thing that isn't working yet, but that isn't a blocker is the
ability of cuda-core to depend on cuda-bindings in the repo. During the
cuda-core build phase, cuda/bindings.pyx isn't found and that causes the
build to fail. I haven't yet investigated that.

copy-pr-bot · 2025-11-07T21:28:17Z

Auto-sync is disabled for ready for review pull requests in this repository. Workflows must be run manually.

Contributors can view more details about this message here.

cpcloud · 2025-11-07T21:30:09Z

/ok to test

cpcloud · 2025-11-10T15:23:55Z

/ok to test

cpcloud · 2025-11-10T15:31:28Z

/ok to test

cpcloud · 2025-11-10T15:42:58Z

/ok to test

cpcloud · 2025-11-10T16:00:54Z

/ok to test

leofang · 2025-11-10T19:45:02Z

Now that we have pixi support, how about adding CI pipelines? (#280) 😉

cpcloud · 2025-11-10T19:50:05Z

Now that we have pixi support, how about adding CI pipelines? (#280) 😉

Something I will look into for sure. I would like to get docs building first (or maybe as a parallel work stream).

copy-pr-bot · 2025-11-11T17:41:32Z

This pull request requires additional validation before any workflows can run on NVIDIA's runners.

Pull request vetters can view their responsibilities here.

Contributors can view more details about this message here.

leofang · 2025-11-11T17:48:26Z

+cuda-version = "13.*"
+
+[environments]
+cu13 = { features = ["cu13", "test", "cython-tests"], solve-group = "cu13" }


I am a bit unhappy having to pass -e cu13 explicitly for every pixi operation. In the next PR we should think about if this is avoidable.

leofang · 2025-11-11T18:51:29Z

+depends-on = [{ task = "build-cython-tests" }]
+
+[target.linux.tasks.test]
+cmd = ["pytest", "$PIXI_PROJECT_ROOT/tests"]


note: I am not sure why, but without adding the tests subdir to the path I hit an error:

(...) tests/cython/test_cython.py . [100%] =========================================================================== 1 passed in 0.75s ============================================================================ ✨ Pixi task (test in cu13): pytest $PIXI_PROJECT_ROOT import cupy as cp from cuda.core.experimental import Device from cuda.core.experimental import LaunchConfig, launch from cuda.core.experimental import Program, ProgramOptions dev = Device(0) dev.set_current() code = r""" extern "C" __global__ void arange(int* a, const int N) { const unsigned int tid = threadIdx.x + blockIdx.x * blockDim.x; for (auto x=tid; x<N; x+=blockDim.x*gridDim.x) { a[x] = x; } } """ prog = Program(code, code_type="c++", options=ProgramOptions(std="c++17")) mod = prog.compile("cubin") ker = mod.get_kernel("arange") s = dev.create_stream() length = 64 data_type = cp.int32 dtype = cp.dtype(data_type) buf = dev.memory_resource.allocate(length * dtype.itemsize, s) config = LaunchConfig(grid=1, block=(32,), stream=s) launch(ker, config, buf, data_type(length)) s.sync() INTERNALERROR> Traceback (most recent call last): INTERNALERROR> File "/local/home/leof/dev/cuda-python/cuda_core/.pixi/envs/cu13/lib/python3.14/site-packages/_pytest/main.py", line 314, in wrap_session INTERNALERROR> config._do_configure() INTERNALERROR> ~~~~~~~~~~~~~~~~~~~~^^ INTERNALERROR> File "/local/home/leof/dev/cuda-python/cuda_core/.pixi/envs/cu13/lib/python3.14/site-packages/_pytest/config/__init__.py", line 1128, in _do_configure INTERNALERROR> self.hook.pytest_configure.call_historic(kwargs=dict(config=self)) INTERNALERROR> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^ INTERNALERROR> File "/local/home/leof/dev/cuda-python/cuda_core/.pixi/envs/cu13/lib/python3.14/site-packages/pluggy/_hooks.py", line 534, in call_historic INTERNALERROR> res = self._hookexec(self.name, self._hookimpls.copy(), kwargs, False) INTERNALERROR> File "/local/home/leof/dev/cuda-python/cuda_core/.pixi/envs/cu13/lib/python3.14/site-packages/pluggy/_manager.py", line 120, in _hookexec INTERNALERROR> return self._inner_hookexec(hook_name, methods, kwargs, firstresult) INTERNALERROR> ~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ INTERNALERROR> File "/local/home/leof/dev/cuda-python/cuda_core/.pixi/envs/cu13/lib/python3.14/site-packages/pluggy/_callers.py", line 167, in _multicall INTERNALERROR> raise exception INTERNALERROR> File "/local/home/leof/dev/cuda-python/cuda_core/.pixi/envs/cu13/lib/python3.14/site-packages/pluggy/_callers.py", line 121, in _multicall INTERNALERROR> res = hook_impl.function(*args) INTERNALERROR> File "/local/home/leof/dev/cuda-python/cuda_core/.pixi/envs/cu13/lib/python3.14/site-packages/_pytest/debugging.py", line 66, in pytest_configure INTERNALERROR> import pdb INTERNALERROR> File "/local/home/leof/dev/cuda-python/cuda_core/.pixi/envs/cu13/lib/python3.14/pdb.py", line 299, in <module> INTERNALERROR> class _PdbInteractiveConsole(code.InteractiveConsole): INTERNALERROR> ^^^^^^^^^^^^^^^^^^^^^^^ INTERNALERROR> AttributeError: module 'code' has no attribute 'InteractiveConsole'

leofang · 2025-11-11T18:51:56Z

+
+[target.linux.tasks.test]
+cmd = ["pytest", "$PIXI_PROJECT_ROOT/tests"]
+#env = { PYTHONPATH = "$PIXI_PROJECT_ROOT/../cuda_python_test_helpers" }


This does not seem necessary...? (I commented it out.)

Running tests from $PIXI_PROJECT_ROOT doesn't work for me without this. That's where we should run the tests from.

This was an intentional choice that I made so that pixi run -e cu13 pytest "just works".

leofang

/ok to test cc83541

leofang · 2025-11-11T19:46:34Z

weird, GitHub response is so slow, and the previous CI trigger did nothing

leofang · 2025-11-11T19:46:46Z

/ok to test b1834b1

github-actions · 2025-11-12T18:23:45Z

Doc Preview CI
Preview removed because the pull request was closed or merged.

cpcloud · 2025-11-12T18:44:28Z

+[target.linux.tasks.build-cython-tests]
+cmd = ["$PIXI_PROJECT_ROOT/tests/cython/build_tests.sh"]
+
+[target.linux.tasks.run-cython-tests]


Is there a point to the complexity of creating a separate task just to run the cython tests and then making that a dependency of the test task?

Why not just run pytest $PIXI_PROJECT_ROOT? If that doesn't work for some reason (e.g., it can't discover the cython tests) then we should pass it on the command line.

Right, Cython tests aren't auto-discoverable from the project root. We added a rule to exclude them. Feel free to simplify the task dependency. I only wanted to make sure it runs as intended, and thought adding 3 lines of code was not too bad.

cpcloud commented Nov 7, 2025

View reviewed changes

Comment thread cuda_core/pixi.toml Outdated

cpcloud force-pushed the pixi-for-cuda-core branch from fb9b67c to e3f2aa2 Compare November 7, 2025 21:30

This comment has been minimized.

Sign in to view

cpcloud mentioned this pull request Nov 10, 2025

feat(build): Changing package.run-dependencies should avoid rebuilding the package if possible prefix-dev/pixi#4906

Closed

cpcloud requested a review from kkraus14 November 10, 2025 15:31

cpcloud requested a review from leofang November 10, 2025 15:47

cpcloud force-pushed the pixi-for-cuda-core branch from 985a8ab to 3fc0891 Compare November 10, 2025 16:00