Hopefully streamline it

img/builder.nix

@@ -23,6 +23,13 @@ let
       destination = "/etc/containers/policy.json";
     }
   );
+  nix-conf = writeTextFile {
+    name = "nix.conf";
+    text = ''
+      extra-experimental-features = nix-command flakes
+    '';
+    destination = "/etc/nix/nix.conf";
+  };
 in
 lib'.mkImage {
   name = name "builder";
@@ -30,6 +37,7 @@ lib'.mkImage {
     buildah
     git
     nix
+    nix-conf
     nix-output-monitor
     nodejs_24
     podman

lib.nix

@@ -2,15 +2,20 @@
 
 {
   basePackages = with pkgs; [
-    bashInteractive
+    (pkgs.buildEnv {
-    cacert
+      name = "base-env";
-    coreutils-full
+      paths = [
-    dockerTools.binSh
+        bashInteractive
-    dockerTools.caCertificates
+        cacert
-    dockerTools.usrBinEnv
+        coreutils-full
-    findutils
+        dockerTools.binSh
-    gnugrep
+        dockerTools.caCertificates
-    gnused
+        dockerTools.usrBinEnv
+        findutils
+        gnugrep
+        gnused
+      ];
+    })
   ];
 
   mkImage =