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/tools/networking/circus/default.nix

@@ -0,0 +1,40 @@
+{ lib, python3 }:
+
+let
+  python = python3.override {
+    self = python;
+    packageOverrides = self: super: {
+      tornado = super.tornado_4;
+    };
+  };
+
+  inherit (python.pkgs) buildPythonApplication fetchPypi iowait psutil pyzmq tornado mock six;
+in
+
+buildPythonApplication rec {
+  pname = "circus";
+  version = "0.16.1";
+
+  src = fetchPypi {
+    inherit pname version;
+    sha256 = "0paccmqwgard2l0z7swcc3nwc418l9b4mfaddb4s31bpnqg02z6x";
+  };
+
+  postPatch = ''
+    # relax version restrictions to fix build
+    substituteInPlace setup.py \
+      --replace "pyzmq>=13.1.0,<17.0" "pyzmq>13.1.0"
+  '';
+
+  checkInputs = [ mock ];
+
+  doCheck = false; # weird error
+
+  propagatedBuildInputs = [ iowait psutil pyzmq tornado six ];
+
+  meta = with lib; {
+    description = "A process and socket manager";
+    homepage = "https://github.com/circus-tent/circus";
+    license = licenses.asl20;
+  };
+}