nixos: Add iso_minimal_new_kernel_no_zfs

Support for ZFS, while desirable, is problematic with newer kernel
releases. The stable ZFS release seldom supports the current newest
kernel version, and this makes the new_kernel iso basically useless as
it cannot be published, and is not often built with new kernel releases.

This uses a dirty workaround to work around the fact it is impossible to
remove a list item from a modules system list type. Since ZFS support is
conditional to being supported on the current platform, we can fake ZFS
not being supported *for the no-zfs build only*. This overlay is only
added when evaluating the iso, nothing else.

1 files changed, 15 insertions, 0 deletions

diff --git a/nixos/modules/installer/cd-dvd/installation-cd-minimal-new-kernel-no-zfs.nix b/nixos/modules/installer/cd-dvd/installation-cd-minimal-new-kernel-no-zfs.nix
new file mode 100644
index 0000000000000..9d09cdbe0206d
--- /dev/null
+++ b/nixos/modules/installer/cd-dvd/installation-cd-minimal-new-kernel-no-zfs.nix
@@ -0,0 +1,15 @@
+{ pkgs, ... }:
+
+{
+  imports = [ ./installation-cd-minimal-new-kernel.nix ];
+
+  # Makes `availableOn` fail for zfs, see <nixos/modules/profiles/base.nix>.
+  # This is a workaround since we cannot remove the `"zfs"` string from `supportedFilesystems`.
+  # The proper fix would be to make `supportedFilesystems` an attrset with true/false which we
+  # could then `lib.mkForce false`
+  nixpkgs.overlays = [(final: super: {
+    zfs = super.zfs.overrideAttrs(_: {
+      meta.platforms = [];
+    });
+  })];
+}