CuPy on AMD GPU causing an ImportError - cupy

Question

I'm trying to use/test the (experimental) AMD GPU support of CuPy (8.1.0). In short: I'm having an ImportError.
I followed the instructions for installing ROCm on a Ubuntu focal machine (with a gfx906/Radeon VII (Vega 20) card).
From the doc I set the mentioned variables (with adjusted HCC_AMDGPU_TARGET), the ROCM_HOME and export PATH=$PATH:/opt/rocm/bin:/opt/rocm/profiler/bin:/opt/rocm/opencl/bin.
pip3 install -v --no-cache-dir cupy succeeded without any complaints. Just a few compiler notes and warnings because of the -v option
Now when I try to import cupy it's throwing an ImportError.
In [1]: import cupy
---------------------------------------------------------------------------
ModuleNotFoundError Traceback (most recent call last)
/usr/local/lib/python3.8/dist-packages/cupy/__init__.py in <module>
19 message='can\'t resolve package from __spec__')
---> 20 from cupy import core # NOQA
21 except ImportError as e:
/usr/local/lib/python3.8/dist-packages/cupy/core/__init__.py in <module>
----> 1 from cupy.core import core # NOQA
2 from cupy.core import internal # NOQA
3
cupy/core/core.pyx in init cupy.core.core()
cupy/core/_routines_manipulation.pyx in init cupy.core._routines_manipulation()
cupy/core/_routines_indexing.pyx in init cupy.core._routines_indexing()
cupy/core/_routines_math.pyx in init cupy.core._routines_math()
cupy/core/_reduction.pyx in init cupy.core._reduction()
cupy/core/_cub_reduction.pyx in init cupy.core._cub_reduction()
ModuleNotFoundError: No module named 'cupy.cuda.cub'
The above exception was the direct cause of the following exception:
ImportError Traceback (most recent call last)
<ipython-input-1-329ec5cf1bc8> in <module>
----> 1 import cupy
/usr/local/lib/python3.8/dist-packages/cupy/__init__.py in <module>
39 original error: {}'''.format(_exc_info[1])) # NOQA
40
---> 41 raise ImportError(_msg) from e
42
43
ImportError: CuPy is not correctly installed.
If you are using wheel distribution (cupy-cudaXX), make sure that the version of CuPy you installed matches with the version of CUDA on your host.
Also, confirm that only one CuPy package is installed:
$ pip freeze
If you are building CuPy from source, please check your environment, uninstall CuPy and reinstall it with:
$ pip install cupy --no-cache-dir -vvvv
Check the Installation Guide for details:
https://docs.cupy.dev/en/latest/install.html
original error: No module named 'cupy.cuda.cub'
What should I do next? What should I look for in the compilation process? Thanks in advance
EDIT On request here the complete stdout and stderr of the installation process and a few io's of the console: https://seafile.cloud.uni-hannover.de/d/68862cd1057e47d180aa/

Answer 1

To summarize the discussion in the comments so far:
For CuPy v8.x (the latest stable releases): Up to v8.1 the offending cupy.cuda.cub module is not built in ROCm/HIP environments, which will hopefully be fixed in v8.2 (see ticket).
For CuPy v9.x (the master branch): It should just work as long as rocPRIM and hipCUB are correctly installed. It's likely that the OP's local environment is not correctly set up, leading to cupy.cuda.cub module not built and thus ImportError.