diff --git a/flake.nix b/flake.nix
index 77ba7a2..9e50405 100644
--- a/flake.nix
+++ b/flake.nix
@@ -8,16 +8,8 @@
   let
     system = "x86_64-linux";
     nixosSystem = import (nixpkgs + "/nixos/lib/eval-config.nix");
-    buildRoots = { pkgs, save }:
-      let
-        buildInner = { package, attr }:
-          if (attr == "")
-          then pkgs.linkFarmFromDrvs "${package.name}" [ package ]
-          else pkgs.linkFarmFromDrvs "${package.name}.${attr}" package.${attr};
-      in pkgs.linkFarmFromDrvs "top-level" (pkgs.lib.mapCartesianProduct buildInner {
-        package = save;
-        attr = [ "" "buildInputs" "nativeBuildInputs" ];
-      });
+    mkRoots = pkgs: list: pkgs.writeText "gcroots.json"
+      (builtins.toJSON (map (x: { drv = x; attrs = x.drvAttrs; }) list));
   in {
     #overlay = import ./overlay.nix;
     nixosConfigurations = {
@@ -120,7 +112,7 @@
       UBOOT_ENV = syspkgs.uboot-env;
       BITSTREAM = syspkgs.bitstream;
       BOOTROM = syspkgs.bootrom;
-      GCROOT = buildRoots { pkgs = syspkgs; save = [ syspkgs.stdenv KERNEL OPENSBI ]; };
+      GCROOT = mkRoots syspkgs [ syspkgs.stdenv KERNEL OPENSBI ];
       shellHook = ''
         echo "Here are the current system pieces:"
         echo " TOPLEVEL  = $TOPLEVEL"
@@ -142,7 +134,7 @@
     in self.outputs.devShells.x86_64-linux.lagarto-ox.overrideAttrs (old:{
         TOPLEVEL = "";
         ROOTFS = "";
-        GCROOT = buildRoots { pkgs = syspkgs; save = [ syspkgs.stdenv old.OPENSBI ]; };
+        GCROOT = mkRoots syspkgs [ syspkgs.stdenv old.OPENSBI ];
       });
 
     devShells.x86_64-linux.default =