fix(test): unblock root pixi run test workflow

`pixi run test` failed at the cuda_bindings build stage because list-form
pixi `cmd` arrays didn't expand `$PIXI_ENVIRONMENT_NAME` reliably, so the
inner per-package `pixi run` calls picked the cuda_bindings default
environment (no cuda-version pin). The conda solver then resolved
cuda-version=12.9 and the build failed with a missing `CUatomicOperation_enum`
(a CUDA-13.x-only symbol).

Wrap the three test-* tasks in `bash -c '...'` so the shell expands
`$PIXI_ENVIRONMENT_NAME` and forward it explicitly via `-e` to each inner
pixi run.

Once the bindings build was unblocked, cuda_core's cython test build hit a
second issue: `cythonize` cannot resolve `cimport cuda.bindings.*` against
pixi-build's editable install, which exposes the cuda namespace package via a
finder hook that Cython's filesystem .pxd resolver does not consult. Replace
the `cythonize` CLI invocation with a small Python wrapper that calls
`Cython.Build.cythonize()` with an explicit `include_path` resolved from the
imported `cuda.bindings` package.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: rparolin

cuda_core/tests/cython/build_tests.py

@@ -0,0 +1,31 @@
+# SPDX-FileCopyrightText: Copyright (c) 2025-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# SPDX-License-Identifier: Apache-2.0
+
+# The Cython CLI has no --include-path flag, and pixi-build's editable install
+# exposes the cuda namespace package through a finder hook that Cython's
+# filesystem .pxd resolver does not consult. Locate the package's parent
+# directory at runtime and pass it to cythonize() explicitly.
+
+import glob
+import os
+from pathlib import Path
+
+import cuda.bindings
+from Cython.Build import cythonize
+from setuptools import setup
+
+HERE = Path(__file__).resolve().parent
+CUDA_PKG_PARENT = Path(cuda.bindings.__file__).parents[2]
+
+# `setup(... build_ext --inplace)` resolves the .so destination relative to cwd
+# and the module's basename, so chdir into HERE before invoking it.
+os.chdir(HERE)
+
+extensions = cythonize(
+    sorted(glob.glob("test_*.pyx")),
+    language_level=3,
+    include_path=[str(CUDA_PKG_PARENT)],
+    compiler_directives={"freethreading_compatible": True},
+)
+
+setup(ext_modules=extensions, script_args=["build_ext", "--inplace"])

cuda_core/tests/cython/build_tests.sh

@@ -15,4 +15,4 @@ else
   exit 1
 fi
 
-cythonize -3 -i -Xfreethreading_compatible=True ${SCRIPTPATH}/test_*.pyx
+python "${SCRIPTPATH}/build_tests.py"

pixi.toml

@@ -19,29 +19,30 @@ PIXI_ENVIRONMENT_NAME = "${PIXI_ENVIRONMENT_NAME/default/cu13}"
 
 # Test Tasks
 # Runs tests across all sub-packages: pathfinder → bindings → core (dependency order)
-# Each sub-package has its own pixi.toml; the -e environment propagates via PIXI_ENVIRONMENT_NAME
+# Each sub-package has its own pixi.toml; the active environment is forwarded
+# explicitly via -e "$PIXI_ENVIRONMENT_NAME" in each inner pixi run.
 #
 # Usage: pixi run test | pixi run -e cu12 test | pixi run -e cu13 test
 [target.linux.tasks.test-pathfinder]
 cmd = [
-    "pixi",
-    "run",
-    "--manifest-path",
-    "$PIXI_PROJECT_ROOT/cuda_pathfinder",
-    "test",
+    "bash",
+    "-c",
+    'pixi run --manifest-path "$PIXI_PROJECT_ROOT/cuda_pathfinder" -e "$PIXI_ENVIRONMENT_NAME" test',
 ]
 
 [target.linux.tasks.test-bindings]
 cmd = [
-    "pixi",
-    "run",
-    "--manifest-path",
-    "$PIXI_PROJECT_ROOT/cuda_bindings",
-    "test",
+    "bash",
+    "-c",
+    'pixi run --manifest-path "$PIXI_PROJECT_ROOT/cuda_bindings" -e "$PIXI_ENVIRONMENT_NAME" test',
 ]
 
 [target.linux.tasks.test-core]
-cmd = ["pixi", "run", "--manifest-path", "$PIXI_PROJECT_ROOT/cuda_core", "test"]
+cmd = [
+    "bash",
+    "-c",
+    'pixi run --manifest-path "$PIXI_PROJECT_ROOT/cuda_core" -e "$PIXI_ENVIRONMENT_NAME" test',
+]
 
 [target.linux.tasks.test]
 depends-on = [