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/diskcache/default.nix

@@ -0,0 +1,58 @@
+{ lib
+, stdenv
+, buildPythonPackage
+, fetchFromGitHub
+, pytest-django
+, pytest-xdist
+, pytestCheckHook
+, pythonOlder
+}:
+
+buildPythonPackage rec {
+  pname = "diskcache";
+  version = "5.4.0";
+  format = "setuptools";
+
+  disabled = pythonOlder "3.6";
+
+  src = fetchFromGitHub {
+    owner = "grantjenks";
+    repo = "python-diskcache";
+    rev = "v${version}";
+    hash = "sha256-c/k8mx/T4RkseDobJ2gtcuom0A6Ewyw4aP2Bk9pxV+o=";
+  };
+
+  checkInputs = [
+    pytest-django
+    pytest-xdist
+    pytestCheckHook
+  ];
+
+  postPatch = ''
+    sed -i "/--cov/d" tox.ini
+  '';
+
+  # Darwin sandbox causes most tests to fail
+  doCheck = !stdenv.isDarwin;
+
+  disabledTests = [
+    # Very time sensitive, can fail on over subscribed machines
+    "test_incr_update_keyerror"
+    # AssertionError: 'default' is not None
+    "test_decr_version"
+    "test_incr_version"
+    "test_get_or_set"
+    "test_get_many"
+  ];
+
+  pythonImportsCheck = [
+    "diskcache"
+  ];
+
+  meta = with lib; {
+    description = "Disk and file backed persistent cache";
+    homepage = "http://www.grantjenks.com/docs/diskcache/";
+    license = licenses.asl20;
+    maintainers = with maintainers; [ costrouc ];
+  };
+}