uboot: (firmwareOdroidC2/C4) don't invoke patch tool, use patches = [] instead

https://github.com/NixOS/nixpkgs/blob/master/pkgs/stdenv/generic/setup.sh#L948
this can do it nicely.

Signed-off-by: Anton Arapov <anton@deadbeef.mx>

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

@@ -0,0 +1,59 @@
+{ lib
+, buildPythonPackage
+, fetchFromGitHub
+, pythonOlder
+, icalendar
+, lxml
+, nose
+, pytz
+, requests
+, six
+, tzlocal
+, vobject
+}:
+
+buildPythonPackage rec {
+  pname = "caldav";
+  version = "0.9.1";
+
+  src = fetchFromGitHub {
+    owner = "python-caldav";
+    repo = pname;
+    rev = "refs/tags/v${version}";
+    hash = "sha256-Gil0v4pGyp5+TnYPjb8Vk0xTqnQKaeD8Ko/ZWhvkbUk=";
+  };
+
+  propagatedBuildInputs = [
+    vobject
+    lxml
+    requests
+    six
+  ];
+
+  checkInputs = [
+    icalendar
+    nose
+    tzlocal
+    pytz
+  ];
+
+  checkPhase = ''
+    nosetests tests
+  '';
+
+  # xandikos and radicale is only a optional test dependency, not available for python3
+  postPatch = ''
+    substituteInPlace setup.py \
+      --replace ", 'xandikos<0.2.4'" "" \
+      --replace ", 'radicale'" ""
+  '';
+
+  pythonImportsCheck = [ "caldav" ];
+
+  meta = with lib; {
+    description = "This project is a CalDAV (RFC4791) client library for Python.";
+    homepage = "https://github.com/python-caldav/caldav";
+    license = licenses.asl20;
+    maintainers = with maintainers; [ marenz dotlambda ];
+  };
+}