cudaPackages_{10*,11*}: warn about upcoming removal (#342112)

nixos/doc/manual/release-notes/rl-2411.section.md

@@ -17,6 +17,10 @@
     [2.24](https://nix.dev/manual/nix/latest/release-notes/rl-2.24).
   Notable changes include improvements to Git fetching, documentation comment support in `nix-repl> :doc`, as well as many quality of life improvements.
 
+- This will be the last release of Nixpkgs to support versions of CUDA prior to CUDA 12.0.
+  These versions only work with old compiler versions that will be unsupported by the time of the Nixpkgs 25.05 release.
+  In future, users should expect CUDA versions to be dropped as the compiler versions they require leave upstream support windows.
+
 - Convenience options for `amdgpu`, open source driver for Radeon cards, is now available under `hardware.amdgpu`.
 
 - [AMDVLK](https://github.com/GPUOpen-Drivers/AMDVLK), AMD's open source Vulkan driver, is now available to be configured as `hardware.amdgpu.amdvlk` option.

pkgs/top-level/cuda-packages.nix

@@ -164,4 +164,10 @@ let
     fixedPoints.extends composedExtension passthruFunction
   );
 in
-cudaPackages
+# We want to warn users about the upcoming deprecation of old CUDA
+# versions, without breaking Nixpkgs CI with evaluation warnings. This
+# gross hack ensures that the warning only triggers if aliases are
+# enabled, which is true by default, but not for ofborg.
+lib.warnIf (cudaPackages.cudaOlder "12.0" && config.allowAliases)
+  "CUDA versions older than 12.0 will be removed in Nixpkgs 25.05; see the 24.11 release notes for more information"
+  cudaPackages

pkgs/top-level/pkg-config/tests.nix

@@ -1,6 +1,6 @@
 # cd nixpkgs
 # nix-build -A tests.pkg-config
-{ lib, stdenv, ... }:
+{ lib, config, stdenv, ... }:
 
 let
   # defaultPkgConfigPackages test needs a Nixpkgs with allowUnsupportedPlatform
@@ -10,7 +10,7 @@ let
   allPkgs = import ../default.nix {
     system = stdenv.hostPlatform.system;
     localSystem = stdenv.buildPlatform.system;
-    config = {
+    config = config // {
       allowUnsupportedSystem = true;
     };
     overlays = [];