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/applications/science/math/pynac/default.nix

@@ -0,0 +1,60 @@
+{ lib, stdenv
+, fetchpatch
+, fetchFromGitHub
+, autoreconfHook
+, pkg-config
+, flint
+, gmp
+, python3
+, singular
+, ncurses
+}:
+
+stdenv.mkDerivation rec {
+  version = "0.7.29";
+  pname = "pynac";
+
+  src = fetchFromGitHub {
+    owner = "pynac";
+    repo = "pynac";
+    rev = "pynac-${version}";
+    sha256 = "sha256-ocR7emXtKs+Xe2f6dh4xEDAacgiolY8mtlLnWnNBS8A=";
+  };
+
+  patches = [
+    # the patch below is included in sage 9.4 and should be included
+    # in a future pynac release. see https://trac.sagemath.org/ticket/28357
+    (fetchpatch {
+      name = "realpartloop.patch";
+      url = "https://git.sagemath.org/sage.git/plain/build/pkgs/pynac/patches/realpartloop.patch?h=9.4.beta5";
+      sha256 = "sha256-1nj0xtlFN5fZKEiRLD+tiW/ZtxMQre1ziEGA0OVUGE4=";
+    })
+  ];
+
+  buildInputs = [
+    flint
+    gmp
+    singular
+    python3
+    ncurses
+  ];
+
+  nativeBuildInputs = [
+    autoreconfHook
+    pkg-config
+  ];
+
+  meta = with lib; {
+    description = "Python is Not a CAS -- modified version of Ginac";
+    longDescription = ''
+      Pynac -- "Python is Not a CAS" is a modified version of Ginac that
+      replaces the depency of GiNaC on CLN by a dependency instead of Python.
+      It is a lite version of GiNaC as well, not implementing all the features
+      of the full GiNaC, and it is *only* meant to be used as a Python library.
+    '';
+    homepage    = "http://pynac.org";
+    license = licenses.gpl2Plus;
+    maintainers = teams.sage.members;
+    platforms   = platforms.unix;
+  };
+}