nixos: Only use compatible kernels for ZFS tests

Right now, the latest kernel is version 5.19, for which there is no
compatible upstream release for ZFS. However, our NixOS VM test always
uses linuxPackages_latest and thus will fail with an evaluation error
most of the time when a new mainline kernel is released.

Since we expose a latestCompatibleLinuxPackages attribute for the ZFS
packages, we already know what's the latest kernel version that is
supported so let's use that instead of linuxPackages_latest.

Signed-off-by: aszlig <aszlig@nix.build>

aszlig 373feb46 58770a33

Changed files
+3 -1
nixos
tests
+3 -1
nixos/tests/zfs.nix
···
let
makeZfsTest = name:
-
{ kernelPackage ? if enableUnstable then pkgs.linuxPackages_latest else pkgs.linuxPackages
, enableUnstable ? false
, extraTest ? ""
}:
···
let
makeZfsTest = name:
+
{ kernelPackage ? if enableUnstable
+
then pkgs.zfsUnstable.latestCompatibleLinuxPackages
+
else pkgs.linuxPackages
, enableUnstable ? false
, extraTest ? ""
}: