1 files changed, 16 insertions(+), 13 deletions(-)

M flake.nix

@@ 3,20 3,23 @@
     "A utility to practise calculating the day of the week of random dates";
 
   outputs = { self, nixpkgs }: {
+    overlay = final: prev: {
+      doomsday = with final;
+        stdenvNoCC.mkDerivation {
+          name = "doomsday";
+          src = self;
+          buildInputs = [ zig ];
+          doConfigure = false;
+          buildPhase = ''
+            export XDG_CACHE_HOME=cachedir
+            mkdir $out
+            zig build install --prefix $out -Drelease-safe=true
+          '';
+          installPhase = "true";
+        };
+    };
 
     defaultPackage.x86_64-linux =
-      with import nixpkgs { system = "x86_64-linux"; };
-      stdenvNoCC.mkDerivation {
-        name = "doomsday";
-        src = self;
-        buildInputs = [ zig ];
-        doConfigure = false;
-        buildPhase = ''
-          export XDG_CACHE_HOME=cachedir
-          mkdir $out
-          zig build install --prefix $out -Drelease-safe=true
-        '';
-        installPhase = "true";
-      };
+      (import nixpkgs { system = "x86_64-linux"; overlays = [ self.overlay ]; }).doomsday;
   };
 }