python/CuTeDSL/prep_editable_install.py downloads nvidia-cutlass-dsl with pip download --no-deps. Since 4.4.0 that wheel is a metadata-only shim (nvidia_cutlass_dsl-4.6.1-py3-none-any.whl is ~10 KB: one .pth + dist-info); the actual libraries live in nvidia-cutlass-dsl-libs-{base,core,cu12,cu13} wheels, under dsl_packages/ rather than python_packages/. The script therefore copies nothing — Summary: 0 lib files, 0 Python files copied — but still logs "Setup completed successfully!" and exits 0. The subsequent pip install -e . / setup.sh --editable also succeeds, and the breakage only surfaces at first use: import cutlass → ModuleNotFoundError: No module named 'cutlass._mlir'.
Repro: fresh venv on x86_64/aarch64 Linux, python prep_editable_install.py at any commit since the script landed.
Fix proposal in the linked PR: detect the shim, follow its nvidia-cutlass-dsl-libs-* Requires-Dist for one CUDA variant, merge all payload dirs, error loudly on empty extraction. PR #3204 previously attempted this but is stale and predates the 4.6.x layout (its default base provider no longer contains lib/*.so).
python/CuTeDSL/prep_editable_install.pydownloadsnvidia-cutlass-dslwithpip download --no-deps. Since 4.4.0 that wheel is a metadata-only shim (nvidia_cutlass_dsl-4.6.1-py3-none-any.whlis ~10 KB: one.pth+ dist-info); the actual libraries live innvidia-cutlass-dsl-libs-{base,core,cu12,cu13}wheels, underdsl_packages/rather thanpython_packages/. The script therefore copies nothing —Summary: 0 lib files, 0 Python files copied— but still logs "Setup completed successfully!" and exits 0. The subsequentpip install -e ./setup.sh --editablealso succeeds, and the breakage only surfaces at first use:import cutlass→ModuleNotFoundError: No module named 'cutlass._mlir'.Repro: fresh venv on x86_64/aarch64 Linux,
python prep_editable_install.pyat any commit since the script landed.Fix proposal in the linked PR: detect the shim, follow its
nvidia-cutlass-dsl-libs-*Requires-Distfor one CUDA variant, merge all payload dirs, error loudly on empty extraction. PR #3204 previously attempted this but is stale and predates the 4.6.x layout (its defaultbaseprovider no longer containslib/*.so).