this ez tho:

    cudnn = super.cudaPackages.cudnn.overrideAttrs (old: {
      buildInputs = (old.buildInputs or []) ++ [ super.cudaPackages.cuda_nvrtc ];

      patchelfFlagsArray = (old.patchelfFlagsArray or []) ++ [
        "--set-rpath" "${super.lib.getLib super.cudaPackages.cuda_nvrtc}/lib:\$ORIGIN"
      ];
    });