diff --git a/nix/devShells.nix b/nix/devShells.nix
index 293af3c..b86a82a 100644
--- a/nix/devShells.nix
+++ b/nix/devShells.nix
@@ -91,12 +91,12 @@
     KANIDM_URL =
       self.nixosConfigurations.sj-srv1.config.containers.webserver.config.services.kanidm.serverSettings.origin;
 
-    shellHook =
+    shellHook = builtins.concatStringsSep "\n" [
       (self.inputs.nixago.lib.${pkgs.system}.make {
         data = self'.formatter.settings;
         output = "treefmt.toml";
         format = "toml";
       }).shellHook
-      + '''';
+    ];
   };
 }
diff --git a/nix/home-manager/programs/vscode/default.nix b/nix/home-manager/programs/vscode/default.nix
index 5fbf2d1..1dbfcea 100644
--- a/nix/home-manager/programs/vscode/default.nix
+++ b/nix/home-manager/programs/vscode/default.nix
@@ -59,7 +59,7 @@ in
       )
       ++ (
         let
-          nix4vscodeConfig = pkgs.writeText "nix4vscode.toml" ''
+          nix4vscodeToml = pkgs.writeText "nix4vscode.toml" ''
             vscode_version = "${config.programs.vscode.package.version}"
 
             [[extensions]]
@@ -70,18 +70,31 @@ in
             publisher_name = "ibecker"
             extension_name = "treefmt-vscode"
           '';
-          nix4vscode =
+          nix4vscodeNix =
             pkgs.runCommand "nix4vscode.nix"
               {
+                # nix4vscode needs internet access
                 __noChroot = true;
-                nativeBuildInputs = [ repoFlake.inputs.nix4vscode.packages.${pkgs.stdenv.system}.default ];
+                requiredSystemFeatures = [ "recursive-nix" ];
+                buildInputs = [
+                  pkgs.nix
+                  pkgs.cacert
+                  repoFlake.inputs.nix4vscode.packages.${pkgs.stdenv.system}.default
+                  # pkgs.strace
+                ];
+                # outputHashAlgo = "sha256";
+                # outputHashMode = "recursive";
+                # outputHash = lib.fakeSha256;
               }
               ''
-                export RUST_BACKTRACE=full
+                # set -x
+                # export RUST_BACKTRACE=full
+                # export RUST_LOG=trace
                 export HOME=$(mktemp -d)
-                nix4vscode ${nix4vscodeConfig} > $out
+                # strace -ffZyyY
+                nix4vscode ${nix4vscodeToml} > $out
               '';
-          nix4vscodeExtensions = builtins.removeAttrs (pkgs.callPackage nix4vscode { }) [
+          nix4vscodeExtensions = builtins.removeAttrs (pkgs.callPackage nix4vscodeNix { }) [
             "override"
             "overrideDerivation"
           ];
diff --git a/nix/os/snippets/nix-settings.nix b/nix/os/snippets/nix-settings.nix
index 6daaaef..6340977 100644
--- a/nix/os/snippets/nix-settings.nix
+++ b/nix/os/snippets/nix-settings.nix
@@ -19,6 +19,7 @@ in
     "nix-command"
     "flakes"
     "ca-derivations"
+    "recursive-nix"
   ];
 
   nix.settings.system-features = [