Arch Linux User Repository

export CUDACXX=/opt/cuda/bin/nvcc also works!

Nice! Could you also try this? It is kind of unusual to use CMAKE_CUDA_COMPILER as an environment variable instead of a CMake parameter.

export CUDACXX=/opt/cuda/bin/nvcc

are you able to build this package yourself outside of a clean chroot?

To be honest, I've never tried that. I always use chroots for non-trivial packages to avoid mysterious issues, and this package is far from a trivial one :)

Jeez, I finally got this to build. This recent thread helped a bit.

  export CXX=/usr/bin/g++-11
  export CUDAHOSTCXX=$CXX
+  export CMAKE_CUDA_COMPILER=/opt/cuda/bin/nvcc

The last line of the diff is the only thing I had to add! Would you consider it adding to the PKGBUIKLD, at least until someone figures out what interveres with building outside of a clean chroot?

And btw, are you able to build this package yourself outside of a clean chroot?

Thank you for your continued help! Unfortunately, it's just not as simple as not having /opt/cuda/bin/nvcc — community/cuda obviously installs this binary, and running /opt/cuda/bin/nvcc --version produces the same output as in your Cmake log.

In the end, I "fixed" this by building this package in a clean chroot. Not ideal, but maybe a proper solultion/answer will come around one day.

Not sure what's going on for you. Here are relevant logs for me:

$ grep -A 10 'Checking whether the CUDA compiler' /var/lib/archbuild/extra-x86_64/yan12125/build/python-torchaudio/src/audio/build/temp.linux-x86_64-3.10/CMakeFiles/CMakeOutput.log
Checking whether the CUDA compiler is NVIDIA using "" matched "nvcc: NVIDIA \(R\) Cuda compiler driver":
nvcc: NVIDIA (R) Cuda compiler driver
Copyright (c) 2005-2022 NVIDIA Corporation
Built on Tue_May__3_18:49:52_PDT_2022
Cuda compilation tools, release 11.7, V11.7.64
Build cuda_11.7.r11.7/compiler.31294372_0
Compiling the CUDA compiler identification source file "CMakeCUDACompilerId.cu" succeeded.
Compiler: /opt/cuda/bin/nvcc
Build flags:
Id flags: --keep;--keep-dir;tmp;-ccbin=/usr/bin/g++-11;-gencode=arch=compute_52,code=sm_52;-gencode=arch=compute_60,code=sm_60;-gencode=arch=compute_62,code=sm_62;-gencode=arch=compute_70,code=sm_70;-gencode=arch=compute_72,code=sm_72;-gencode=arch=compute_75,code=sm_75;-gencode=arch=compute_80,code=sm_80;-gencode=arch=compute_86,code=sm_86;-gencode=arch=compute_86,code=sm_86 -v

$ grep -r CMAKE_CUDA_ARCH /var/lib/archbuild/extra-x86_64/yan12125/build/python-torchaudio/src/audio/build/temp.linux-x86_64-3.10
/var/lib/archbuild/extra-x86_64/yan12125/build/python-torchaudio/src/audio/build/temp.linux-x86_64-3.10/CMakeCache.txt:CMAKE_CUDA_ARCHITECTURES:UNINITIALIZED=52-real;60-real;62-real;70-real;72-real;75-real;80-real;86-real;86
/var/lib/archbuild/extra-x86_64/yan12125/build/python-torchaudio/src/audio/build/temp.linux-x86_64-3.10/CMakeFiles/3.23.2/CMakeCUDACompiler.cmake:set(CMAKE_CUDA_ARCHITECTURES_ALL "35;37;50;52;53;60;61;62;70;72;75;80;86;87")
/var/lib/archbuild/extra-x86_64/yan12125/build/python-torchaudio/src/audio/build/temp.linux-x86_64-3.10/CMakeFiles/3.23.2/CMakeCUDACompiler.cmake:set(CMAKE_CUDA_ARCHITECTURES_ALL_MAJOR "35;50;60;70;80")

I got Compiler: /opt/cuda/bin/nvcc but you have Compiler: CMAKE_CUDA_COMPILER-NOTFOUND. Maybe that program is somehow missing or broken for you?

Still having the same sort of problems, a month later:

-- Caffe2: Protobuf version 3.20.1
-- Found CUDA: /opt/cuda (found version "11.7")
-- The CUDA compiler identification is unknown
CMake Error at /usr/share/cmake/Modules/CMakeDetermineCUDACompiler.cmake:633 (message):
  Failed to detect a default CUDA architecture.

  Compiler output:

Call Stack (most recent call first):
  /usr/lib64/cmake/Caffe2/public/cuda.cmake:41 (enable_language)
  /usr/lib64/cmake/Caffe2/Caffe2Config.cmake:88 (include)
  /usr/lib64/cmake/Torch/TorchConfig.cmake:68 (find_package)
  CMakeLists.txt:87 (find_package)

-- Configuring incomplete, errors occurred!
See also "/tmp/makepkg/python-torchaudio/src/audio/build/temp.linux-x86_64-3.10/CMakeFiles/CMakeOutput.log".
See also "/tmp/makepkg/python-torchaudio/src/audio/build/temp.linux-x86_64-3.10/CMakeFiles/CMakeError.log".

CMakeError.log contains the following:

Checking whether the CUDA compiler is NVIDIA using "" did not match "nvcc: NVIDIA \(R\) Cuda compiler driver":
Checking whether the CUDA compiler is Clang using "" did not match "(clang version)":
Compiling the CUDA compiler identification source file "CMakeCUDACompilerId.cu" failed.
Compiler: CMAKE_CUDA_COMPILER-NOTFOUND 
Build flags: 
Id flags:  -v

The output was:
No such file or directory


Compiling the CUDA compiler identification source file "CMakeCUDACompilerId.cu" failed.
Compiler: CMAKE_CUDA_COMPILER-NOTFOUND 
Build flags: 
Id flags:  -v

The output was:
No such file or directory

Note that cmake fails at CMakeDetermineCUDACompiler.cmake:633:

  if(NOT CMAKE_CUDA_COMPILER_ID STREQUAL "NVIDIA" OR _CUDA_CMP0104 STREQUAL "NEW")
    set(CMAKE_CUDA_ARCHITECTURES "${architectures_detected}" CACHE STRING "CUDA architectures")

    if(NOT CMAKE_CUDA_ARCHITECTURES)
      message(FATAL_ERROR "Failed to detect a default CUDA architecture.\n\nCompiler output:\n${CMAKE_CUDA_COMPILER_PRODUCED_OUTPUT}")
    endif()

What is the value of CMAKE_CUDA_ARCHITECTURES in your case? What should it be? (It's empty for me.)

Maybe worth another try with /usr/local/cuda

Forget about /usr/local/coda, that was just a temporary bug in how CUDA was packaged on Arch (see also my previous comment).

I switched to GCC 11 and it works with /opt/cuda. Maybe worth another try with /usr/local/cuda :)

Hmm that's strange. community/cuda installs to /opt/cuda, but your logs mentioned /usr/local/cuda. Maybe some other packages or scripts installs them for you.

It's true that cuda installs to /opt, as confirmed by yay -Ql cuda. However, when I sudo rm -rf /usr/local/cuda, then yay -R cuda, and finally reinstall using yay -S cuda, /usr/local/cuda appears again! It's not a symlink to /opt/cuda, but the contents of the two folders appear to be identical (certainly, nvcc -V is the same in both folders). Hence, I think we've stumbled on a bug (a totally extraneous duplicate is installed). I'll report it in a bit.

Perhaps the hack(s) you describe don't quite apply to /usr/local/cuda, which would explain why my build keeps failing.

Good catch noticing /usr/local/cuda in my logs!

never messed around with installing nvidia stuff another way.

Hmm that's strange. community/cuda installs to /opt/cuda, but your logs mentioned /usr/local/cuda. Maybe some other packages or scripts installs them for you.

That this may be he root of the problem seems to accord with various reports on the web. https://gitlab.kitware.com/cmake/cmake/-/issues/23322

Thanks for the link! I have a guess now: nvcc inside /usr/local/cuda rejects gcc 12 and causes a mysterious CMake error. On the other hand, community/cuda comes with a hack [1] to accept whatever gcc versions, so CMake does not complain.

Are you sure cmake picks up on the env variable you've changed?

Before I added USE_CUDA=0, I got an error invalid type argument of unary ‘*’ when compiling compute_alphas.cu, and now it's gone for me. Somehow CMake still checks for CUDA even with USE_CUDA=0. Maybe that flag only disables invoking nvcc for compiling *.cu files.

[1] https://github.com/archlinux/svntogit-community/blob/packages/cuda/trunk/PKGBUILD#L124

I have community/cuda installed, never messed around with installing nvidia stuff another way. I reinstalled it for the fun of it, but no luck.

CUDA 11.7 ... is still incompatible with GCC 12

That this may be he root of the problem seems to accord with various reports on the web. See https://gitlab.kitware.com/cmake/cmake/-/issues/23322

I disabled CUDA altogether for now

Perhaps this doesn't quite work yet? Are you sure cmake picks up on the env variable you've changed?