pkgs.writeErofsLayers,profiles/ch-runner: MVE

$ nix-build -A examples.dummy.config.debug.closure.erofs.list | xargs
cat | xargs du -h
749M    /nix/store/bzfv5x6lycq6hzhjv6d6vlk1q8fdg9di-base0.erofs
24M     /nix/store/hp41jfq36y0mmjrzqilyh3jfsvqic3kb-nixos.erofs

$ nix run -f . examples.dummy.config.uvms.cloud-hypervisor.runner
...
<<< Welcome to NixOS 25.11pre-git (x86_64) - ttyS0 >>>

nixos login:

The definition of the `pkgs` fixpoint was moved to pkgs/default.nix.
For that, dirToAttrs was moved to lib/, imported ad hoc

pkgs/default.nix

@@ -0,0 +1,23 @@
+{ lib, newScope }:
+let
+  dirToAttrs = import ../lib/dirToAttrs.nix { inherit lib; };
+in
+lib.makeScope newScope (
+  self:
+  dirToAttrs ./.
+    [
+      (
+        path: fname: _:
+        if fname == "default.nix" then null else lib.strings.removeSuffix ".nix" fname
+      )
+    ]
+    (
+      name: fpath: typ:
+      if typ == "regular" then
+        self.callPackage fpath { }
+      else if typ == "directory" && builtins.pathExists (fpath + "/package.nix") then
+        self.callPackage (fpath + "/package.nix") { }
+      else
+        null
+    )
+)