Derivation in seperate file

default.nix

@@ -0,0 +1,28 @@
+{ pkgs
+, scdoc
+, xclip
+, stdenvNoCC
+, ...
+}:
+stdenvNoCC.mkDerivation rec {
+  pname = "irs";
+  version = "0.3";
+  src = ./src;
+  nativeBuildInputs = with pkgs; [
+    scdoc
+  ];
+
+  buildPhase = ''
+    for page in $(find manpages -type f); do
+      scdoc < $page > $(basename $page .scd)
+    done
+  '';
+
+  installPhase = ''
+    mkdir -p $out/{share/man/man1,bin,share/zsh/site-functions}
+    cp bin/* $out/bin/
+    cp completions/* $out/share/zsh/site-functions/
+    cp *.1 $out/share/man/man1/
+  '';
+
+}

flake.lock

@@ -20,11 +20,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1697655685,
-        "narHash": "sha256-79Kuv+QdgsVc+rkibuAgWHnh8IXrLBTOKg5nM0Qvux0=",
+        "lastModified": 1701053011,
+        "narHash": "sha256-8QQ7rFbKFqgKgLoaXVJRh7Ik5LtI3pyBBCfOnNOGkF0=",
         "owner": "nixos",
         "repo": "nixpkgs",
-        "rev": "80c1aab725151632ddc2a20caeb914e76dd0673c",
+        "rev": "5b528f99f73c4fad127118a8c1126b5e003b01a9",
         "type": "github"
       },
       "original": {

flake.nix

@@ -7,31 +7,8 @@
   flake-utils.lib.eachDefaultSystem ( system:
   let pkgs = import nixpkgs { inherit system; };
   in{
-    packages = rec {
-      default = pkgs.stdenvNoCC.mkDerivation rec {
-        pname   = "irs";
-        version = "0.2";
-
-        src = ./src;
-
-        buildInputs = with pkgs; [
-          coreutils
-          scdoc
-        ];
-
-        buildPhase = ''
-          for page in $(find manpages -type f); do
-            scdoc < $page > $(basename $page .scd)
-          done
-        '';
-
-        installPhase = ''
-          mkdir -p $out/{share/man/man1,bin,share/zsh/site-functions}
-          cp bin/* $out/bin/
-          cp completions/* $out/share/zsh/site-functions/
-          cp *.1 $out/share/man/man1/
-        '';
-      };
+    packages = {
+      default = pkgs.callPackage ./default.nix {};
     };
   });
 }