python310Packages.curtsies: disable on older Python releases

- make backports-cached-property optional

pkgs/development/python-modules/curtsies/default.nix

@@ -1,13 +1,13 @@
-{ stdenv
-, lib
+{ lib
+, stdenv
+, backports-cached-property
+, blessed
 , buildPythonPackage
+, cwcwidth
 , fetchPypi
-, pythonOlder
-, blessed
-, backports-cached-property
 , pyte
 , pytestCheckHook
-, cwcwidth
+, pythonOlder
 }:
 
 buildPythonPackage rec {
@@ -15,15 +15,18 @@ buildPythonPackage rec {
   version = "0.4.1";
   format = "pyproject";
 
+  disabled = pythonOlder "3.7";
+
   src = fetchPypi {
     inherit pname version;
     hash = "sha256-YtEPNJxVOEUwZVan8mY86WsJjYxbvEDa7Hpu7d4WIrA=";
   };
 
   propagatedBuildInputs = [
-    backports-cached-property
     blessed
     cwcwidth
+  ] ++ lib.optionals (pythonOlder "3.8") [
+    backports-cached-property
   ];
 
   checkInputs = [
@@ -32,10 +35,10 @@ buildPythonPackage rec {
   ];
 
   meta = with lib; {
-    broken = stdenv.isDarwin;
     description = "Curses-like terminal wrapper, with colored strings!";
     homepage = "https://github.com/bpython/curtsies";
     license = licenses.mit;
     maintainers = with maintainers; [ flokli ];
+    broken = stdenv.isDarwin;
   };
 }