feat(aquamarine): track linuxPackages_latest (#478)

Assisted-by: DeepSeek Harness (deepseek-flash)

hosts/idols-aquamarine/ROCM.md

@@ -18,10 +18,11 @@ by a maintainer).
 - **ROCm today**: system requirements list `AMD Radeon AI PRO R9700 | RDNA4 | gfx1201 | ✅`.
   **verified**
   ([requirements](https://rocm.docs.amd.com/projects/install-on-linux/en/latest/reference/system-requirements.html))
-- **This repository**: nixpkgs `f45c6f0` provides `rocmPackages.clr` and `rocmPackages.rocm-smi`
-  7.2.3 and Mesa 26.2.4; the host runs the nixpkgs default kernel (6.18.x LTS), not
-  `linuxPackages_latest` (7.2.8), which is what the first bring-up booted. **verified** (checked by
-  `nix eval`)
+- **This repository**: the primary nixpkgs input `f71476e8` provides `rocmPackages.clr` 7.2.3.
+  Aquamarine selects `linuxPackages_latest` for newer amdgpu/KFD fixes; this does not establish
+  compatibility with ROCm 10.1 containers. On 2026-10-20, before activating this change, the host
+  reported kernel/driver 6.18.54, host CLR 7.2.3 and inference-container ROCm 7.2.4. The first
+  bring-up also used `linuxPackages_latest` (7.2.8).
 - **Mesa**: "initial GFX12 (RDNA4) support on RADV" landed in 25.0.0. **verified**
   ([notes](https://gitlab.freedesktop.org/mesa/mesa/-/blob/main/docs/relnotes/25.0.0.rst))
 - **Kernel**: amdgpu has no static `1002:7551` entry; its ID table ends with

hosts/idols-aquamarine/hardware-amd-gpu.nix

@@ -55,6 +55,10 @@
     enable = true;
   };
 
+  # ROCm 10.1 is available: https://rocm.docs.amd.com/en/latest/.
+  # nixpkgs still ships 7.2.x while the upgrade awaits split reviews, LLVM/OpenMP
+  # fixes and compatibility work: https://github.com/NixOS/nixpkgs/pull/573885.
+  # Inference containers carry their own ROCm userspace.
   # The ROCm OpenCL ICD, which is also what HIP consumers resolve for compute.
   hardware.amdgpu.opencl.enable = true;
 

hosts/idols-aquamarine/hardware-configuration.nix

@@ -26,12 +26,9 @@
   boot.loader.efi.canTouchEfiVariables = true;
   boot.loader.efi.efiSysMountPoint = "/boot";
 
-  # The nixpkgs default (`linuxPackages`) is the stable/LTS line, which is what a
-  # server should run; `linuxPackages_latest` is for chasing new hardware. The
-  # R9700 (Navi 48) only needs the 6.14 AMD validates for it, so the default is
-  # far ahead of the requirement. See ./ROCM.md.
-  # https://github.com/nixpkgs/nixpkgs/blob/nixos-unstable/pkgs/top-level/linux-kernels.nix
-  boot.kernelPackages = pkgs.linuxPackages;
+  # Track newer amdgpu/KFD fixes for the R9700 inference containers.
+  # https://github.com/NixOS/nixpkgs/blob/nixos-unstable/pkgs/top-level/linux-kernels.nix
+  boot.kernelPackages = pkgs.linuxPackages_latest;
 
   boot.initrd.availableKernelModules = [
     "xhci_pci"

outputs/x86_64-linux/tests/idols-aquamarine/expected.nix

@@ -11,7 +11,7 @@
   cachePersistent = true;
   userUnitDirsPersistent = true;
   rootlessPodmanEnabled = true;
-  stableKernel = true;
+  latestKernel = true;
   btopShowsRadeon = true;
   btopReadsIgpu = true;
   igpuMediaStackInstalled = true;

outputs/x86_64-linux/tests/idols-aquamarine/expr.nix

@@ -53,8 +53,8 @@ in
     ];
   rootlessPodmanEnabled = cfg.virtualisation.podman.enable;
 
-  # A server tracks the nixpkgs default (stable/LTS) kernel, not `-latest`.
-  stableKernel = cfg.boot.kernelPackages.kernel.version == eval.pkgs.linuxPackages.kernel.version;
+  latestKernel =
+    cfg.boot.kernelPackages.kernel.version == eval.pkgs.linuxPackages_latest.kernel.version;
   btopShowsRadeon = cfg.modules.btop.package == eval.pkgs.btop-rocm;
   # CAP_PERFMON inside the wrapper is what the i915 iGPU needs.
   btopReadsIgpu = cfg.modules.btop.perfmon;