cudaPackages.cudatoolkit: replace with symlinkJoin

nixos/doc/manual/release-notes/rl-2405.section.md

@@ -307,6 +307,12 @@ The pre-existing [services.ankisyncd](#opt-services.ankisyncd.enable) has been m
 
 - The `cudaPackages` package scope has been updated to `cudaPackages_12`.
 
+- The deprecated `cudaPackages.cudatoolkit` has been replaced with a
+  symlink-based wrapper for the splayed redistributable CUDA packages. The
+  wrapper only includes tools and libraries necessary to build common packages
+  like e.g. tensorflow. The original runfile-based `cudatoolkit` is still
+  available as `cudatoolkit-legacy-runfile`.
+
 - The `halloy` package was updated past 2024.5 which introduced a breaking change by switching the config format from YAML to TOML. See https://github.com/squidowl/halloy/releases/tag/2024.5 for details.
 
 - Ada packages (libraries and tools) have been moved into the `gnatPackages` scope. `gnatPackages` uses the default GNAT compiler, `gnat12Packages` and `gnat13Packages` use the respective matching compiler version.

pkgs/development/cuda-modules/cudatoolkit/default.nix

@@ -411,7 +411,7 @@ backendStdenv.mkDerivation rec {
   };
 
   meta = with lib; {
-    description = "A compiler for NVIDIA GPUs, math libraries, and tools";
+    description = "The deprecated runfile-based CUDAToolkit installation (a compiler for NVIDIA GPUs, math libraries, and tools)";
     homepage = "https://developer.nvidia.com/cuda-toolkit";
     platforms = [ "x86_64-linux" ];
     license = licenses.nvidiaCuda;

pkgs/development/cuda-modules/cudatoolkit/redist-wrapper.nix

@@ -0,0 +1,86 @@
+{
+  lib,
+  symlinkJoin,
+  backendStdenv,
+  cudaOlder,
+  cudatoolkit-legacy-runfile,
+  cudaVersion,
+  cuda_cccl ? null,
+  cuda_cudart ? null,
+  cuda_cuobjdump ? null,
+  cuda_cupti ? null,
+  cuda_cuxxfilt ? null,
+  cuda_gdb ? null,
+  cuda_nvcc ? null,
+  cuda_nvdisasm ? null,
+  cuda_nvml_dev ? null,
+  cuda_nvprune ? null,
+  cuda_nvrtc ? null,
+  cuda_nvtx ? null,
+  cuda_profiler_api ? null,
+  cuda_sanitizer_api ? null,
+  libcublas ? null,
+  libcufft ? null,
+  libcurand ? null,
+  libcusolver ? null,
+  libcusparse ? null,
+  libnpp ? null,
+}:
+
+let
+  getAllOutputs = p: [
+    (lib.getBin p)
+    (lib.getLib p)
+    (lib.getDev p)
+  ];
+  hostPackages = [
+    cuda_cuobjdump
+    cuda_gdb
+    cuda_nvcc
+    cuda_nvdisasm
+    cuda_nvprune
+  ];
+  targetPackages = [
+    cuda_cccl
+    cuda_cudart
+    cuda_cupti
+    cuda_cuxxfilt
+    cuda_nvml_dev
+    cuda_nvrtc
+    cuda_nvtx
+    cuda_profiler_api
+    cuda_sanitizer_api
+    libcublas
+    libcufft
+    libcurand
+    libcusolver
+    libcusparse
+    libnpp
+  ];
+
+  # This assumes we put `cudatoolkit` in `buildInputs` instead of `nativeBuildInputs`:
+  allPackages = (map (p: p.__spliced.buildHost or p) hostPackages) ++ targetPackages;
+in
+
+if cudaOlder "11.4" then
+  cudatoolkit-legacy-runfile
+else
+  symlinkJoin rec {
+    name = "cuda-merged-${cudaVersion}";
+    version = cudaVersion;
+
+    paths = builtins.concatMap getAllOutputs allPackages;
+
+    passthru = {
+      cc = lib.warn "cudaPackages.cudatoolkit is deprecated, refer to the manual and use splayed packages instead" backendStdenv.cc;
+      lib = symlinkJoin {
+        inherit name;
+        paths = map (p: lib.getLib p) allPackages;
+      };
+    };
+
+    meta = with lib; {
+      description = "A wrapper substituting the deprecated runfile-based CUDA installation";
+      license = licenses.nvidiaCuda;
+    };
+  }

pkgs/top-level/cuda-packages.nix

@@ -69,7 +69,11 @@ let
     backendStdenv = final.callPackage ../development/cuda-modules/backend-stdenv.nix { };
 
     # Loose packages
-    cudatoolkit = final.callPackage ../development/cuda-modules/cudatoolkit { };
+
+    # TODO: Move to aliases.nix once all Nixpkgs has migrated to the splayed CUDA packages
+    cudatoolkit = final.callPackage ../development/cuda-modules/cudatoolkit/redist-wrapper.nix { };
+    cudatoolkit-legacy-runfile = final.callPackage ../development/cuda-modules/cudatoolkit { };
+
     saxpy = final.callPackage ../development/cuda-modules/saxpy { };
     nccl = final.callPackage ../development/cuda-modules/nccl { };
     nccl-tests = final.callPackage ../development/cuda-modules/nccl-tests { };