Simplify flake.nix

flake.nix

@@ -35,23 +35,6 @@
             crossSystem = system;
           }));
 
-      nixpkgsFor = forAllSystems ({ system, localSystem, crossSystem }:
-        if localSystem == crossSystem then
-          import nixpkgs {
-            inherit system;
-            overlays = [ self.overlay nimble.overlay ];
-          }
-        else
-          import nixpkgs {
-            inherit localSystem;
-            crossSystem = {
-              system = crossSystem;
-              useLLVM = true;
-            };
-            config.allowUnsupportedSystem = true;
-            overlays = [ self.overlay nimble.overlay ];
-          });
-
     in rec {
 
       overlay =
@@ -164,19 +147,33 @@
 
         });
 
-      legacyPackages =
-        # The nixpkgs.legacyPackages after overlaying
-        # and with some additional Genode packages
-        forAllSystems
-        ({ system, localSystem, crossSystem }: nixpkgsFor.${system});
-      # pass thru Nixpkgs
+      /* The nixpkgs.legacyPackages after overlaying
+         and with some additional Genode packages.
+      */
+      legacyPackages = let f = import nixpkgs;
+      in forAllSystems ({ system, localSystem, crossSystem }:
+        if localSystem == crossSystem then
+          f {
+            inherit system;
+            overlays = [ self.overlay nimble.overlay ];
+          }
+        else
+          f {
+            inherit localSystem;
+            crossSystem = {
+              system = crossSystem;
+              useLLVM = true;
+            };
+            config.allowUnsupportedSystem = true;
+            overlays = [ self.overlay nimble.overlay ];
+          });
 
       packages =
         # Genode native packages, not packages in the traditional
         # sense in that these cannot be installed within a profile
         forAllCrossSystems ({ system, localSystem, crossSystem }:
           nixpkgs.lib.filterAttrs (n: v: v != null)
-          nixpkgsFor.${system}.genodePackages);
+          self.legacyPackages.${system}.genodePackages);
 
       devShell =
         # Development shell for working with the
@@ -232,7 +229,7 @@
             inherit system localSystem crossSystem;
             pkgs = self.legacyPackages.${system};
           } // {
-            ports = nixpkgsFor.${localSystem}.symlinkJoin {
+            ports = self.legacyPackages.${localSystem}.symlinkJoin {
               name = "ports";
               paths = (builtins.attrValues
                 self.packages.${system}.genodeSources.ports);