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/cffi/default.nix

@@ -0,0 +1,46 @@
+{ lib, stdenv, buildPythonPackage, isPyPy, fetchPypi, pytestCheckHook,
+  libffi, pkg-config, pycparser
+}:
+
+if isPyPy then null else buildPythonPackage rec {
+  pname = "cffi";
+  version = "1.15.0";
+
+  src = fetchPypi {
+    inherit pname version;
+    sha256 = "920f0d66a896c2d99f0adbb391f990a84091179542c205fa53ce5787aff87954";
+  };
+
+  outputs = [ "out" "dev" ];
+
+  buildInputs = [ libffi ];
+
+  nativeBuildInputs = [ pkg-config ];
+
+  propagatedBuildInputs = [ pycparser ];
+
+  postPatch = lib.optionalString stdenv.isDarwin ''
+    # Remove setup.py impurities
+    substituteInPlace setup.py \
+      --replace "'-iwithsysroot/usr/include/ffi'" "" \
+      --replace "'/usr/include/ffi'," "" \
+      --replace '/usr/include/libffi' '${lib.getDev libffi}/include'
+  '';
+
+  # The tests use -Werror but with python3.6 clang detects some unreachable code.
+  NIX_CFLAGS_COMPILE = lib.optionalString stdenv.cc.isClang
+    "-Wno-unused-command-line-argument -Wno-unreachable-code -Wno-c++11-narrowing";
+
+  # Lots of tests fail on aarch64-darwin due to "Cannot allocate write+execute memory":
+  # * https://cffi.readthedocs.io/en/latest/using.html#callbacks
+  doCheck = !stdenv.hostPlatform.isMusl && !(stdenv.isDarwin && stdenv.isAarch64);
+
+  checkInputs = [ pytestCheckHook ];
+
+  meta = with lib; {
+    maintainers = with maintainers; [ domenkozar lnl7 ];
+    homepage = "https://cffi.readthedocs.org/";
+    license = licenses.mit;
+    description = "Foreign Function Interface for Python calling C code";
+  };
+}