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/gunicorn/default.nix

@@ -0,0 +1,40 @@
+{ lib, buildPythonPackage, fetchPypi, isPy27
+, coverage
+, mock
+, pytest
+, pytest-cov
+, setuptools
+}:
+
+buildPythonPackage rec {
+  pname = "gunicorn";
+  version = "20.1.0";
+  disabled = isPy27;
+
+  src = fetchPypi {
+    inherit pname version;
+    sha256 = "e0a968b5ba15f8a328fdfd7ab1fcb5af4470c28aaf7e55df02a99bc13138e6e8";
+  };
+
+  propagatedBuildInputs = [ setuptools ];
+
+  checkInputs = [ pytest mock pytest-cov coverage ];
+
+  prePatch = ''
+    substituteInPlace requirements_test.txt --replace "==" ">=" \
+      --replace "coverage>=4.0,<4.4" "coverage"
+  '';
+
+  # better than no tests
+  checkPhase = ''
+    $out/bin/gunicorn --help > /dev/null
+  '';
+
+  pythonImportsCheck = [ "gunicorn" ];
+
+  meta = with lib; {
+    homepage = "https://github.com/benoitc/gunicorn";
+    description = "WSGI HTTP Server for UNIX";
+    license = licenses.mit;
+  };
+}