python3Packages.plac: disable on older Python releases

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

@@ -2,14 +2,19 @@
 , buildPythonPackage
 , fetchPypi
 , python
+, pythonOlder
 }:
+
 buildPythonPackage rec {
   pname = "plac";
   version = "1.3.5";
+  format = "setuptools";
+
+  disabled = pythonOlder "3.7";
 
   src = fetchPypi {
     inherit pname version;
-    sha256 = "sha256-OL3YZNBFD7dIGTqoF7nEWKj1MZ+/l7ImEVHPwKWBIJA=";
+    hash = "sha256-OL3YZNBFD7dIGTqoF7nEWKj1MZ+/l7ImEVHPwKWBIJA=";
   };
 
   checkPhase = ''
@@ -17,6 +22,10 @@ buildPythonPackage rec {
     ${python.interpreter} -m unittest discover -p "*test_plac*"
   '';
 
+  pythonImportsCheck = [
+    "plac"
+  ];
+
   meta = with lib; {
     description = "Parsing the Command Line the Easy Way";
     homepage = "https://github.com/micheles/plac";