I'm making some progress, now I can build llama-cpp-python with cuda, but unfortunately at runtime, the python app doesn't see the GPU 😭
these lines from llama.cpp derivation caught my attention :

  # It's necessary to consistently use backendStdenv when building with CUDA support,
  # otherwise we get libstdc++ errors downstream.
  # cuda imposes an upper bound on the gcc version, e.g. the latest gcc compatible with cudaPackages_11 is gcc11
  effectiveStdenv = if cudaSupport then cudaPackages.backendStdenv else stdenv;
....
effectiveStdenv.mkDerivation (finalAttrs: {
....

in my case I'm not making a derivation but I'm building a python package using pkgs.python311.pkgs.buildPythonPackage
could it be the reason why gpu/cuda is not used at runtime ?

not making a derivation b

buildPythonPackage is a wrapper around mkDerivation

python app doesn't see the GPU

Usually that means you need to add a DT_RUNPATH or LD_LIBRARY_PATH somewhere, pointing at ${addDriverRunpath.driverLink}/lib

In reply to @ss:someonex.net

python app doesn't see the GPU

Usually that means you need to add a DT_RUNPATH or LD_LIBRARY_PATH somewhere, pointing at ${addDriverRunpath.driverLink}/lib

In reply to @ss:someonex.net

python app doesn't see the GPU

Usually that means you need to add a DT_RUNPATH or LD_LIBRARY_PATH somewhere, pointing at ${addDriverRunpath.driverLink}/lib

Could you please help me on the syntax ? The closest I can get is below and has no effect (in my shellHook) :

export LD\_LIBRARY\_PATH=${pkgs.lib.makeLibraryPath \[
pkgs.addDriverRunpath.driverLink
\]}
export DT\_RUNPATH=${pkgs.lib.makeLibraryPath \[
pkgs.addDriverRunpath.driverLink
\]}

Could you please help me on the syntax ? The closest I can get is below and has no effect (in my shellHook) :

export LD_LIBRARY_PATH=${pkgs.lib.makeLibraryPath [
pkgs.addDriverRunpath.driverLink
]}
export DT_RUNPATH=${pkgs.lib.makeLibraryPath [
pkgs.addDriverRunpath.driverLink
]}

I'm trying to package positron here is my attempt: https://github.com/b-rodrigues/nixpkgs/blob/positron/pkgs/by-name/po/positron/package.nix
but I get this error message when trying to build

b-rodrigues@localhost:~/Documents/github_repos/nixpkgs(master)$ nix-shell -I nixpkgs=. -p R rPackages.dplyr positron
this derivation will be built:
  /nix/store/qh59xjk5cz4dq44y0jixma219sr9xb0f-Positron-2024.06.1-27.drv
building '/nix/store/qh59xjk5cz4dq44y0jixma219sr9xb0f-Positron-2024.06.1-27.drv'...
Running phase: unpackPhase
tar: ./usr/share/positron/chrome-sandbox: Cannot change mode to rwsr-xr-x: Operation not permitted
tar: Exiting with failure status due to previous errors
dpkg-deb: error: tar subprocess returned error exit status 2
error: builder for '/nix/store/qh59xjk5cz4dq44y0jixma219sr9xb0f-Positron-2024.06.1-27.drv' failed with exit code 2;
       last 4 log lines:
       > Running phase: unpackPhase
       > tar: ./usr/share/positron/chrome-sandbox: Cannot change mode to rwsr-xr-x: Operation not permitted
       > tar: Exiting with failure status due to previous errors
       > dpkg-deb: error: tar subprocess returned error exit status 2
       For full logs, run 'nix log /nix/store/qh59xjk5cz4dq44y0jixma219sr9xb0f-Positron-2024.06.1-27.drv'.