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/pyenchant/default.nix

@@ -0,0 +1,44 @@
+{ lib, stdenv
+, buildPythonPackage
+, isPy27
+, fetchPypi
+, enchant2
+}:
+
+buildPythonPackage rec {
+  pname = "pyenchant";
+  version = "3.2.2";
+  disabled = isPy27;
+
+  src = fetchPypi {
+    inherit pname version;
+    sha256 = "1cf830c6614362a78aab78d50eaf7c6c93831369c52e1bb64ffae1df0341e637";
+  };
+
+  propagatedBuildInputs = [ enchant2 ];
+
+  postPatch = let
+    libext = stdenv.hostPlatform.extensions.sharedLibrary;
+  in ''
+    # Use the $PYENCHANT_LIBRARY_PATH envvar lookup line to hard-code the
+    # location of the nix enchant-2 library into _enchant.py.
+    #
+    # Also, they hardcode a bad path for Darwin in their library search code;
+    # This code should never be hit, but in case it does, we don't want to have
+    # it "accidentally" work by pulling something from /opt.
+    substituteInPlace enchant/_enchant.py                  \
+      --replace 'os.environ.get("PYENCHANT_LIBRARY_PATH")' \
+                "'${enchant2}/lib/libenchant-2${libext}'"  \
+      --replace '/opt/local/lib/' ""
+  '';
+
+  # dictionaries needed for tests
+  doCheck = false;
+
+  meta = with lib; {
+    description = "pyenchant: Python bindings for the Enchant spellchecker";
+    homepage = "https://github.com/pyenchant/pyenchant";
+    license = licenses.lgpl21;
+  };
+
+}