Fix build in full nix sandbox

flake.nix

@@ -19,7 +19,7 @@
 
       filter = nix-filter.lib;
 
-      nodejs = pkgs.nodejs-18_x;
+      nodejs = pkgs.nodejs_20;
 
       src = filter {
         root = ./.;
@@ -36,17 +36,21 @@
       deps = builtins.attrValues (removeAttrs packageLock.packages [ "" ])
         ++ builtins.attrValues (removeAttrs (packageLock.dependencies or {} ) [ "" ])
       ;
-      tarballs = map (p: pkgs.fetchurl { url = p.resolved; hash = p.integrity; }) deps;
+      depTarballs = map (p: pkgs.fetchurl { url = p.resolved; hash = p.integrity; }) deps;
       tarballsFile = pkgs.writeTextFile {
         name = "tarballs";
-        text = builtins.concatStringsSep "\n" tarballs;
+        text = (builtins.concatStringsSep "\n" depTarballs) + "\n";
       };
 
       # build npm cache
       ashenearth_modules = pkgs.stdenv.mkDerivation {
         inherit src;
 
-        name = "node_modules";
+        name = "ashenearth_nodemodules";
+
+        nativeBuildInputs = [
+          nodejs
+        ];
 
         buildInputs = [ nodejs ];