xborders: setup.py in separate file

modules/xborders/setup.py

@@ -0,0 +1,12 @@
+from setuptools import setup
+
+setup(
+    name='@pname@',
+    version='@version@',
+    author='deter0',
+    description='@desc@',
+    install_requires=['pycairo', 'requests', 'PyGObject'],
+    scripts=[
+        'xborders',
+    ],
+)

modules/xborders/xborders.nix

@@ -28,20 +28,14 @@ with pkgs; callPackage python3Packages.buildPythonPackage rec {
     pygobject3
   ];
 
-  preBuild = ''
-    cat >setup.py <<'EOF'
-    from setuptools import setup
-    setup(
-      name='${pname}',
-      version='${version}',
-      author='deter0',
-      description='${meta.description}',
-      install_requires=['pycairo', 'requests', 'PyGObject'],
-      scripts=[
-        'xborders',
-      ],
-    )
-    EOF
+  postPatch = let
+    setup = pkgs.substituteAll {
+      src = ./setup.py;
+      desc = meta.description; # "description" is reserved 
+      inherit pname version;
+    };
+  in ''
+    ln -s ${setup} setup.py
   '';
 
   meta = with lib; {