build from source instead of using prebuilt wheel

flake.nix

@@ -6,11 +6,17 @@
   outputs = {nixpkgs, ...}: let
     system = "x86_64-linux";
     pkgs = import nixpkgs {inherit system;};
+    version = "0.6";
+    pname = "cassowary";
+    src = pkgs.fetchFromGitHub {
+      owner = "casualsnek";
+      repo = pname;
+      tag = version;
+      hash = "sha256-qsawsi3erjIXIT0JXKx54P2gV8c+RHThef0iw1AEHyo=";
+    };
   in {
     packages.${system}.default = pkgs.python312Packages.buildPythonPackage {
-      pname = "cassowary";
-      version = "0.6";
-      format = "wheel";
+      inherit version pname src;
       propagatedBuildInputs = [
         pkgs.python312Packages.libvirt
         pkgs.python312Packages.pyqt5
@@ -19,20 +25,19 @@
       ];
       buildInputs = [
         pkgs.libsForQt5.qttools
+        pkgs.python312Packages.setuptools
       ];
       nativeBuildInputs = [
         pkgs.libsForQt5.wrapQtAppsHook
       ];
+      sourceRoot = "${src.name}/app-linux";
       # Arguments to be passed to `makeWrapper`, only used by buildPython*
       preFixup = ''
         qtWrapperArgs+=("''${gappsWrapperArgs[@]}")
         # You can manually patch scripts using: wrapQtApp "$out/bin/myapp". TODO: check when it's required.
         wrapQtApp $out/bin/cassowary
       '';
-      src = pkgs.fetchurl {
-        url = "https://github.com/casualsnek/cassowary/releases/download/0.6/cassowary-0.6-py3-none-any.whl";
-        hash = "sha256-WWvCE1yKhz50AE8s/UG4IYT2eJKxFZinTrOBs5AGt9g=";
-      };
+      format = "pyproject";
     };
   };
 }